Dramatic CCTV footage has emerged which appears to show the moment a massive car bomb went off in the Turkish capital, amid reports of multiple deaths and injuries.

Witnesses in Ankara described seeing a huge explosion seen next to the main bus station in the Kizilay neighbourhood, home to a number of government agencies and parliamentary buildings.

Several people are reported killed and many injured, in what the NTV news channel described as a car-bombing, though this has not been confirmed.

In the video, a number of cars can be seen moving past a bus in a road next to Ankara's main square, Kizilay. A large explosion can then be seen, setting nearby vehicles on fire.

Dozens of emergency vehicles responded on the scene, while police sealed off the area and pushed onlookers and journalists back, warning there could be a second bomb.

Dogan Asik, 28, told the Associated Press he was on a bus nearby when the explosion occurred. 

"We were thrown further back into the bus from the force of the explosion," said Asik, who sustained injuries on his face and arm.

The incident comes just three weeks after a suicide car bombing in the capital targeted buses carrying military personnel, killing 29 people.

That attack was claimed by a Kurdish militant group which is an offshoot of the outlawed rebel group, the Kurdistan Workers' Party, or PKK.