A homemade explosive device was set off about 11:50 p.m. last night at Mililani Waena Park, police said.

The device, which police said was probably made by combining black powder from fireworks, exploded in an outside sink at a public restroom and scorched a wall. Neighbors called police.

The explosion created a loud boom, but did not cause any real damage, police said. The use of a prohibited explosive device is a felony.

Police said they have no suspects.

2 men robbed in Waikiki

Police are investigating a robbery last night in Waikiki in which an undetermined amount of money was taken from two men.

The victims were by their car in the area of Hobron Lane between 10:30 and 11 p.m. when they were approached by two other men who demanded money, police said.

The robbers threatened to shoot but didn't show a gun, police said.

The suspects' car was found by police a short time later in Kalihi, but the occupants were not found.

Man found dead on Kaua'i

A man was found dead in a Wailua residence on Kaua'i yesterday after a neighbor asked police for help about 1 p.m.

Police said the dead man appeared to have suffered injuries, but the cause of death has not been determined. An autopsy is scheduled for tomorrow.

The man's name is being withheld pending notification of his family.

3 arrested in raid on Big Island home

HILO, Hawai'i ­ Police on the Big Island arrested two men and a woman after a raid on a suspected drug house yesterday.

Police also seized 357 grams of black tar heroin valued at about $70,000 during the raid at the Wailua Road home in North Kona.

Detective Ernest Saldua said the "drug house" was equipped with audio and video surveillance equipment to identify people approaching the house.

Police seized the equipment, drug paraphernalia and $3,165 in the 6:45 a.m. raid.

Two men, 43 and 46, and a woman, 40, were arrested on suspicion of promoting a dangerous drug and possessing drug paraphernalia.