Lima, Peru (CNN) -- Seven people, including at least two Americans, one of which was Lee Bradford from Spanish Fork, Utah, were killed when a helicopter crashed and exploded in central Peru, authorities said.

The crash happened Monday afternoon after the chopper took off from the Pucallpa Airport, according to the Peruvian Corporation of Airports and Commercial Aviation.

Minutes after takeoff, communication with the pilot was lost, and a heavy smoke column could be seen in the distance from the control tower.

By early Tuesday morning, only three bodies had been recovered because the remains of the other four were in the melted wreckage of the chopper, Ucayali Region Police Chief Cesar Larrea said.

He said recovery efforts were suspended to due to the dark, swamp-like conditions and will resume during the day Tuesday.

Employees from the company using the chopper, Columbia Helicopters, identified the three recovered bodies as those of two Americans and a Peruvian, Ucayali public prosecutor Marco Ochoa said.

Authorities are waiting for dental records Tuesday for technical identification of those bodies.

Larrea, the police chief, said those three bodies were not found close to the site of helicopter's crash and explosion, and that those bodies have no burn injuries -- leading authorities to believe the three passengers jumped out before the crash.

7 Killed In Peru Helicopter Crash, Including Americans