BAGHDAD — Suicide bombers killed 13 people in a pair of attacks Monday around the Sunni city of Ramadi in what local officials said was part of a power struggle between al-Qaida and tribes that have broken with the terror network.

In all, at least 68 people were killed or found dead nationwide Monday, police said. They included the bullet-riddled bodies of 30 men found in Baghdad — the apparent victims of sectarian death squads.

All but two were found in west Baghdad, including 17 in the Amil neighborhood where Sunni politicians have complained of renewed attacks by Shiite militiamen, according to a police official who spoke on condition of anonymity because he was not supposed to release those details.

The power struggle among the Sunnis, which surfaced last year, could prove decisive in the U.S. campaign to win over significant portions of the Sunni community, which has formed the bedrock of the insurgency.

The first of the Ramadi area attacks happened about noon in a market on the northwest outskirts of the city, killing eight people and wounding 13, said police Col. Tariq Youssef.

SENATE OKS DRUG CERTIFICATION MEASURE

WASHINGTON — The Senate effectively killed a bid to allow consumers to buy their prescription medicines abroad Monday, requiring U.S. officials to certify the safety and effectiveness of such drugs.

The certification amendment, passed on a 49-40 vote, would require health officials to do something they have long said they cannot.

Because of that, the vote undercut a second measure that would permit prescription drug imports from Food and Drug Administration-approved sources in Canada, Australia, Europe, Japan and New Zealand.

The Bush administration opposes allowing imports of prescription drugs, and the White House had threatened a veto.

Sen. Bernie Sanders, I-Vt., called the certification amendment, introduced by Sen. Thad Cochran, R-Miss., a "poison pill" for the drug-imports legislation. Sen. Byron Dorgan, D-N.D., acknowledged it voided his bid to allow the purchase of drugs abroad.

QUEEN ELIZABETH II GRACES WHITE HOUSE

WASHINGTON — In a slip of the tongue, President Bush brought roars of laughter to the White House welcoming ceremony for Queen Elizabeth II.

The president stumbled on a line in his speech Monday, saying that the queen had dined with 10 U.S. presidents and had helped the United States "celebrate its bicentennial in 17. ..." Bush caught himself and corrected the date to 1976. He paused as if to see if the queen had taken offense.

"She gave me a look that only a mother could give a child," the president said with a smile.

Bush focused his formal remarks on how the United States and Britain, allies in Iraq and Afghanistan, were standing together in the fight against terrorism. In just four minutes, he mentioned "freedom" and "liberty" seven times and he told the queen: "Your majesty, I appreciate your leadership during these times of danger and decision."

By contrast, the queen said her fifth U.S. visit was an occasion to "step back from our current preoccupations."

RESIGNATIONS AFFLICT BUSH NATIONAL SECURITY TEAM

WASHINGTON — Top members of President Bush's national security team are leaving in one of the earliest waves of departures from a second-term administration — nearly two years before Bush's time ends.

As rancor in the nation rises over handling of the war in Iraq, at least 20 senior aides have either retired or resigned from important posts at the White House, Pentagon and State Department in the past six months.

Some have left for lucrative positions in the private sector. Some have gone to academic or charitable institutions. The latest was Deputy National Security Adviser J.D. Crouch, who spoke favorably of Bush's policies as he announced he was leaving last week.

Turnover is normal as an administration nears its end, but "this is a high number," said Paul Light, a professor of public service at New York University and an expert on government.

"You would expect to see vacancies arise as things wind down, but it's about six months early for this kind of a mass exodus," he said.

OBAMA LAUDS FUEL-EFFICIENT VEHICLES

DETROIT — Democratic presidential candidate Barack Obama on Monday faulted U.S. automakers for failing to do what foreign manufacturers have accomplished in producing fuel-efficient vehicles.

Uttering words not often spoken in Detroit, Obama said U.S. energy policy must change in order to help domestic automakers answer the rising global demand for efficient autos.

"For years, while foreign competitors were investing in more fuel-efficient technology for their vehicles, American automakers were spending their time investing in bigger, faster cars," the Illinois senator told business and political leaders.

Obama said his plan encourages domestic automakers to make fuel-efficient hybrid vehicles by giving them healthcare assistance for retirees. Federal financial assistance would cover 10 percent — up to $7 billion — of automakers' annual legacy health care costs through 2017, under Obama's plan, which would require automakers to invest at least half of their healthcare savings into technology to produce fuel-efficient cars.

As a second choice, Obama's plan would provide $3 billion to automakers over 10 years to help retool plants to make fuel-efficient cars and trucks.

2 MORE VICTIMS, 1 SURVIVOR FOUND IN KANSAS

GREENSBURG, Kan. — Rescue teams searching the rubble that was once Greensburg found two more victims and a survivor, raising the death toll from a powerful tornado that largely obliterated the small town to at least 10, authorities said Monday.

The massive tornado, an enhanced F-5 with wind estimated at 205 mph, was part of a weekend of violent storms that tore across the Plains and were also blamed for two other deaths in Kansas.

Little remained standing in Greensburg Monday but the grain elevator as the town's 1,500 residents were allowed back in to check their property. The tornado demolished every business on the main street. Churches lost their steeples, trees were stripped of their branches, and neighborhoods were flattened. Officials estimate as much as 95 percent of the town was destroyed.

One of the latest victims was found under debris in the middle of town, city administrator Steve Hewitt said. The other body was pulled from a nearby lake.

Rescue teams also found a survivor as they searched the wreckage on Sunday, two days after the tornado hit, providing hope for other discoveries, said Kansas Highway Patrol spokesman Ron Knoefel. He did not release details on the survivor's identity or condition, and authorities had not identified any of the victims.

ASTRONOMERS SPOT EXPLODING STAR

WASHINGTON — A massive exploding faraway star — the brightest supernova astronomers have ever seen — has scientists wondering whether a similar celestial fireworks show may light up the sky much closer to Earth sometime soon.

The discovery, announced Monday by NASA, drew oohs and aahs for months from the handful of astronomers who peered through telescopes to see the fuzzy remnants of the spectacular explosion after it was first spotted last fall.

Using a variety of Earth and space telescopes, astronomers found a giant exploding star that they figure has shined about five times brighter than any of the hundreds of supernovae ever seen before, said discovery team leader Nathan Smith of the University of California at Berkeley. The discovery was first made last September by a graduate student in Texas.

"This one is way above anything else," Smith said. "It's really astonishing."

Smith said the star, SN2006gy, "is a special kind of supernova that has never been seen before." He called the star "freakily massive" at 150 times the mass of the sun.

ABC GIVES 'LOST' AN END DATE IN 2010

LOS ANGELES — ABC is attempting to rescue once-hot "Lost" by ending the show — in 2010. Bowing to the fact that convention isn't working for the drama about plane-crash survivors on a surreal island, the network is taking the unusual step of turning "Lost" into a limited-run series.

It will run for three shorter and uninterrupted seasons until its "highly anticipated and shocking finale" in the 2009-10 season, ABC said Monday.

The series, which saw its ratings drop this season amid complaints about scheduling, an increasingly meandering plot and unpopular new characters, still must prove itself to disenchanted viewers to survive.

"Due to the unique nature of the series, we knew it would require an end date to keep the integrity and strength of the show consistent throughout and to give the audience the payoff they deserve," ABC Entertainment President Stephen McPherson said in a statement.

Typically, networks milk a series until it runs dry of ratings and then drop the ax.

DOW PASSES 13,300 FOR FIRST TIME

NEW YORK — Wall Street closed mostly higher Monday, though technology stocks struggled to hold onto gains during the session, as a $27 billion bid by Alcoa Inc. for Canadian aluminum rival Alcan Inc. buoyed blue chip issues. The Dow Jones industrials passed 13,300 for the first time and had yet another record close.

The move by Alcoa, one of the 30 stocks that make up the Dow, gave much of the market a lift Monday as investors often regard merger and acquisition activity as a bullish bet by companies on corporate profit. A pullback in Yahoo Inc. depressed tech shares.

With little earnings and economic data to go on, investors were waiting for further signals to try to determine where stocks might be headed and whether Wall Street's record rally will continue. They were also awaiting the Federal Reserve's decision Wednesday on interest rates.

Monday afternoon, the Fed reported that consumers boosted their borrowing in March at the fastest pace in four months. The report showed that consumer credit increased at a brisk annual rate of 6.7 percent in March.