Officials say the blast was caused by a vehicle packed with explosives close to the city's main square, Kizilay
At least 34 people have been killed and 125 wounded - 19 seriously - in a car bombing in Turkey's capital, the country's security officials have said.
The explosion happened in the centre of Ankara around 6.45pm local time, authorities say.
"The blast was caused by a vehicle packed with explosives close to Kizilay square," a statement said.
Kizilay is a main shopping and transport hub close to the city's embassy area.
The car bomb exploded close to a bus and caused several vehicles to catch fire.
The windows of shops that line the busy square were shattered in the blast.
Dogan Asik, 28, told the Associated Press he was on a bus when the explosion happened.
"We were thrown further back into the bus from the force of the explosion," said Mr Asik, who sustained injuries on his face and arm.
Police sealed off the area and pushed onlookers back, warning there could be a second explosion.
There has been no immediate claim of responsibility and Turkey's pro-Kurdish party The Peoples' Democratic Party, HDP, issued a statement condemning the attack, saying it shares "the huge pain felt along with our citizens".
This is significant because the party is often accused of being a wing of the outlawed Kurdistan Workers' Party, or PKK - an accusation it denies.
Turkish Prime Minister Ahmet Davutoglu has called an emergency security meeting.
It comes just weeks after at least 28 people were killed in another car bombing in the city.
Kurdish militants claimed responsibility for that attack.
Fianna Fáil has condemned the suspected bombing "in the strongest possible terms".
The party's Foreign Affairs Spokesperson Brendan Smith said, “this is an extremely shocking attack... The loss of life and scale of injuries from this explosion is very serious.
“Officials in Turkey are reporting that this attack may have been caused by a suicide car bombing which would be of serious concern for stability in Turkey," he added.