Two people have been killed after a helicopter crashed into a boat on the Mississippi River.

The crash triggered a fire that sent large black plumes of smoke into the air.

Officials from the National Transportation Safety Board (NTSB) said the incident happened when the helicopter became entangled with electrical cables.

It then struck the barge, which had no passengers.

Emergency response teams from both Missouri and Illinois made their way to the scene on Thursday morning, close to the town of Alton, 20 miles north of St Louis.

Cpl Dallas Thompson of the Missouri state highway patrol told the Associated Press two people on the aircraft were killed and that there were no other reported injuries.