GUATEMALA CITY -- A small plane carrying U.S. humanitarian workers crashed in a field in eastern Guatemala on Sunday, killing 10 people, including five Americans, an aviation official and a survivor said.

The pilot called in engine trouble about 45 minutes after takeoff and tried to make an emergency landing, Civil Aviation director Jose Carlos said. Eight passengers were killed, along with the Guatemalan pilot and co-pilot, Carlos said.

He said five of the passengers killed were Americans, but the nationalities of the other three had not been determined. Four other Americans on board were injured and were being airlifted to a hospital in the capital.

Sarah Jensen, a 19-year-old who survived the crash with minor cuts and bruises, said she and her family were headed to a village in the area of El Estor to build homes for CHOICE Humanitarian, a group based in West Jordan, Utah.

Her brother and father were killed in the crash, and her mother had serious burns and contusions. The family is from Amery, Wisconsin, Jensen told The Associated Press in a brief interview at the hospital.

Amery is a small town about 30 miles east of the Minnesota state line.

It was unclear if the other Americans were also with CHOICE Humanitarian. The group did not return calls Sunday afternoon.

Aero Ruta Maya, the airline operating the plane, said only 12 people were on the plane, including the pilots, a discrepancy that could not immediately be resolved.

Joanne de Bickford, who said she was the daughter of the airline's owner and was helping manage the crisis, confirmed there were Americans on board. She said the airline did not know how many people died.

The army provided a list of passengers, but the names appeared to be garbled. The U.S. Embassy did not immediately return calls seeking comment.