SAN JUAN, Puerto Rico — A Puerto Rico National Guard helicopter has crashed in the ocean after returning from a drug raid, with all six people aboard feared dead, officials said today.

Two of the passengers are prosecutors with the local justice department and the other four are officials with the National Guard, three of them crew members, said U.S. Coast Guard spokesman Ricardo Castrodad.

Crews are searching for those aboard, and Police Chief Jose Figueroa Sancha told NotiUno radio station that officials found the fuselage of the UH-72 helicopter just north of the island.

The helicopter was returning from the neighboring island of Vieques when it disappeared late Monday just north of the coastal city of Rio Grande. Neither pilot reported any problems during the flight, said National Guard Gen. Antonio Vicens.

The prosecutors worked for the division of organized crimes, said Justice Secretary Guillermo Somoza.

The helicopter was flying at about 400 feet and was fairly new, having been bought in May 2009, Vicens said.

It apparently changed its route, but it is unclear why.

The officials had been in Vieques to help serve 43 arrest warrants after a seven-month investigation into drug dealers on an island popular with tourists.