A large explosion in the Turkish capital, Ankara, has killed at least 18 people, Turkish officials said.
A vehicle full of explosives was detonated as military buses were passing by, according to the Ankara governor’s office.
More than 40 people were injured in the blast, which happened in an area close to parliament and Turkey’s military headquarters.
Deputy Prime Minister Bekir Bozdag called it an “act of terrorism”.
Large plumes of smoke were seen rising from the area and witnesses said the blast was heard all over the city.
Ambulances and fire engines were sent to the scene.
Turkey’s Prime Minister, Ahmet Davutoglu, has cancelled a trip to Brussels.
Turkey has been hit by a serious of attacks recently, and there have been increasing concerns that the country could be targeted by another big attack, the BBC’s Selin Girit in Istanbul reports.
Last October, an attack at a peace march left at least 99 people dead in Ankara.
Turkey has become more involved in the Syrian conflict and has faced security threats from different groups, including IS and the outlawed Kurdistan Workers’ Party (PKK).