LIMA (Reuters) - Seven employees of U.S.-based Columbia Helicopters were killed in a helicopter crash on Monday in Peru's Amazon jungle, the company said on Tuesday.

Columbia, known for its tandem rotor cargo helicopters that are used in logging and oil exploration work, said four of the employees were based in the United States and three in Peru.

"This is a very sad day for Columbia Helicopters," said Michael Fahey, the president of the company from Portland, Oregon. "We may operate globally, but we are still very much a family."

The helicopter crashed minutes after taking off from Pucallpa, about 485 miles east of Lima, on a flight to Tarapoto. It apparently tried to drop cargo as it lost power, and at least three people leapt from the aircraft, Peru's La Republica newspaper, citing witnesses, reported on Tuesday.

There were no survivors, a Peruvian judicial official said.

Local media reports initially said on Monday that those on board worked for Petrominerales Ltd, a Canadian-based oil exploration firm focused on Latin America. Petrominerales later denied those reports.

Columbia said it would work with witnesses and authorities to conduct a thorough investigation into the crash.

(Reporting by Terry Wade; Editing by Paul Simao)