MOMBASA, Kenya — It's supposed to be the peak tourist season on Kenya's warm Indian Ocean coast, but the violence and uncertainty following last month's disputed election have driven away tens of thousands of visitors.

Now officials are warning of a major slowdown that could have broad implications for the East African country, whose growing tourism industry is a pillar of the economy and the source of more than 500,000 jobs.

"If tourism as a sector collapses, it will trigger a collapse of the entire economy," said Ongonga Achieng, the head of the Kenya Tourist Board.

Since President Mwai Kibaki claimed a disputed election victory, more than 600 people have been killed in politically motivated clashes, and a quarter-million people have been driven from their homes. On Friday, opposition leaders called off protests and said they would launch boycotts of companies owned by top allies of Kibaki, who they charge stole the election.

But yesterday, they called for continued protests.

Television images of rioting and protests have prompted many Americans and Europeans to cancel vacations in Kenya, which is known for its spectacular safaris and perpetually warm beaches. Throughout the coastal region, hotels and resorts that usually operate at 85 percent capacity at this time of year are now only 20 percent full.

Although no tourists have been hurt in the fighting and the unrest has largely spared the coastal areas and other vacation hotspots, the U.S. Embassy issued a travel alert last week that said, "The situation in Kenya is volatile and subject to change on short notice."

The embassy has had a travel warning for Kenya for more than four years, due largely to a 2002 attack by al-Qaida suspects on a hotel outside of Mombasa that's popular with Israeli tourists. Despite the warnings, however, 100,000 Americans visited Kenya last year, a record.

Tourism contributes $900 million to Kenya's economy and a tenth of the country's jobs, but the industry figures to take a hit this year. Officials had expected 315,000 visitors in the first three months but have reduced their estimate to 134,450. Expected earnings have been slashed by one-third, from $300 million for the quarter to slightly more than $100 million.

Before the elections, the expansive, 610-bed Sun and Sand beach resort in the town of Kilifi was fully booked. Now it hosts slightly more than 100 guests who are spread around the palatial five-star hotel crafted in Swahili-style architecture.

On a recent afternoon, rather than mixing drinks, bartender Andrew Charo polished cabinets housing fine wines and whiskies until they gleamed in the sun. There were hardly any customers around.

"I will be out of work if this trend goes on," Charo said. "This is where I earn my bread, and if I go down my family goes down with me."

Along the coast, where an estimated four in five residents depend on tourism for their livelihood, experts fear that 20,000 jobs could be lost by the end of the month. An additional 120,000 jobs could be lost by March.

"We are now digging our graves if things don't change," said Tasneem Adamji, the chair of the local branch of the Kenya Association of Tour Operators.

Sandra Peck, a tourist from Manchester, England, said she wasn't deterred by the travel warnings.

"In the tourist areas there have been no skirmishes, so we haven't really been affected," Peck said.