A helicopter believed to be involved in aid operations in Haiti crashed late Thursday in the western Dominican Republic, killing two men who were aboard, officials said.

"Up to now we have two bodies, the pilot and co-pilot," said Dominican Civil Aeronautics Institute spokesman Pedro Jimenez.

The nationality of the two killed was not immediately clear.

The R44 helicopter, a light four-seat civil aircraft produced by the Robinson Helicopter Company of the United States, crashed around 7:00 p.m. (23:00 GMT) in the province of Dajabon, 190 miles northwest of the capital Santo Domingo, Jimenez said.

The aircraft was en route from the Haitian capital Port-au-Prince to Santiago, in the northern Dominican Republic.

"Apparently it was one of those helicopters involved in the rescue in Haiti" in the aftermath of last month's massive earthquake there, said Jimenez, who added that the pilots did not inform air traffic controllers of any flight difficulties.

Authorities launched an investigation into the crash, the official said.