SANTO DOMINGO, Dominican Republic (AP) — A U.S.-owned helicopter involved in Haiti aid efforts crashed in the Dominican Republic, killing the two Americans on board, an official said Friday.

Pilot John Ward and co-pilot James Jalove were returning from Haiti on Thursday night when their R44 II helicopter crashed into a mountain in the western Dominican province of Dajabon, said Dominican Civil Aviation Institute spokesman Pedro Jimenez. Jimenez did not release the men’s home states or towns.

One of the firefighters at the scene, Angel Belliard, said one of the two men was dressed as a doctor — he did not elaborate — and that emergency responders found medicine scattered around the crash site.

U.S. Embassy spokesman David Searby said he could not confirm the crash or the reported identities and nationalities of the victims. Protocol requires that the Embassy contact next of kin before confirming the deaths of U.S. citizens.

The helicopter was owned by JAJ Investments Limited in Naples, Florida, according to U.S. Federal Aviation Administration documents. The company could not be reached immediately for comment.