At least 18 people are dead and 45 others injured after a vehicle laden with explosives detonated in the centre of the Turkish capital of Ankara. 

The target of the blast was a convoy of military service vehicles which were waiting at traffic lights when the nearby car exploded, according to Ankara governor Mehmet Kiliclar. 

The car bomb exploded in the administrative heart of the capital, near the armed forces' headquarters, parliament and government buildings. 

Plumes of smoke were seen rising over the city and the powerful blast was heard across several neighbourhoods, sending residents rushing to their balconies in a panic. 
Ambulances and fire engines were sent to the scene, which is near the Turkish military headquarters and the parliament.  

A health ministry official said the authorities were still trying to determine the number of dead and wounded, who had been taken to several hospitals in the area.

Initial reports claimed just the blast killed five people and injured 10 others, but that number was raised substantially by the city's governor Mehmet Kiliclar.

Turkish broadcaster NTV said the explosion happened near a residential block for top-level military staff.
'I heard a huge explosion. There was smoke and a really strong smell even though we were blocks away,' said a witness. 

'We could immediately hear ambulance and police car sirens rushing to the scene.' 

Turkish Prime Minister Ahmet Davutoglu has cancelled his planned trip to Brussels following the explosion, according to an official in the prime minister's office. 

Mr Davutoglu was due to leave later Wednesday for Brussels to meet a number of EU leaders on Thursday for discussions on the migrant crisis ahead of a full summit of the 28-member bloc. 

The spokesman for the ruling Justice and Development Party (AKP), Omer Celik, said he strongly condemned the attack, Turkish media reported. 

Turkish police have cordoned off the area.