Two people were feared dead after a rare cargo plane crashed in the far north of the United States on Tuesday, troopers in Alaska said.

The Douglas DC-4, one of just a handful left in the world, came down just after leaving Fairbanks International Airport in the middle of the vast state.

Alaska State Troopers said the plane had taken off shortly before 10:00 am (1800 GMT) and crashed near the Tanana River moments later.

"The aircraft slid into a steep hill on the bank of the river where it caught fire," the state's Department of Public Safety said.

"No survivors have been located."

Unconfirmed pictures on social media showed a large fire engulfing trees.

The Federal Aviation Authority (FAA) said it would be involved in a probe into the incident.

"The FAA and the National Transportation Safety Board will investigate," a statement said.

"The NTSB will be the lead agency and provide any updates."

The Douglas DC-4 was originally built during World War II.

Some of them were used in the Berlin airlift in 1948 and 1949 when Soviet forces cut off supplies to parts of the German city under Allied control.