WILLEMSTAD, Curacao (AP) _ Four Haitians were in jail Thursday on air piracy charges after trying to hijack to New York an Antillean Airlines flight enroute from Haiti to this Dutch Caribbean island.

Police said the four were not armed when they attempted to hijack ALM Flight 974 Wednesday night. The plane left Miami between 4 p.m. and 5 p.m. for Curacao, with a stopover in Haiti.

''They wanted to go to New York and were under the impression that they were going to New York,'' the airline's spokesman Robin Visser said Thursday. He said the plane's captain fooled the hijackers into believing the airport in Curacao was really New York.

Visser said Wednesday night that the hijackers ultimately wanted to be flown to Israel.

He said that after the plane left Haiti, a Haitian man told a flight attendant he had put in a bathroom a box of explosives that could be detonated by a Haitian army colonel in a submarine somewhere in the Caribbean.

After the Haitians were arrested in Curacao when the plane arrived, the crew found a small box in the bathroom. Police said Thursday they were still investigating its contents.

Attorney General Robert Pietersz Thursday identified the group's leader as Joseph Pierre Lamy, 37. He said the other three were a 29-year-old man and two women aged 27 and 35. He said he did not know the names of the three.

He said the four have been charged with air piracy and will be tried in Curacao.

He said they face a maximum sentence of 10 years. He said authorities still have not determined the motive for the hijacking, partly due to trouble communicating with the Haitians, who speak only Creole and broken French.

Visser said the DC-9 Super 80 returned to normal service Thursday.

He said one of the estimated 100 passengers was slightly injured Wednesday night in the rush to leave the plane after the captain ordered its immediate evacuation after landing.