Kurdish militants have claimed responsibility for the attack.
A car bomb killed at least 27 people at a crowded transport hub in the Turkish capital of Ankara on Sunday and wounded at least 75 more, the second such attack in the administrative heart of the city in less than a month.
The blast, which could be heard several kilometers away, sent burning debris showering down over an area a few hundred meters from the Justice and Interior Ministries, a top courthouse, and the former office of the prime minister.
Police helicopters hovered overhead as a large cloud of smoke rose over the city center.
One senior security official told Reuters initial findings suggested the attack had been carried out by the Kurdistan Workers Party (PKK) or an affiliated militant group, but there was no immediate claim of responsibility.
The government blamed the PKK and Kurdish militants in Syria for the previous car bombing just a few blocks away on Feb. 17, which killed 29 people, most of them soldiers. That attack struck near Turkey’s military headquarters, parliament and other key government institutions.
President Tayyip Erdogan spoke with Interior Minister Efkan Ala by telephone after Sunday’s blast, presidential sources said.
“A total of 27 of our citizens were killed when a car exploded at Kizilay’s Guven Park, and close to 75 of our wounded citizens were taken to various hospitals for treatment,” the Ankara governor’s office said in a statement.
A second senior security official said gunfire was heard after the blast.
State broadcaster TRT said the car had exploded at a major transport hub, hitting a bus carrying some 20 people near the central Guven Park and Kizilay Square. It said the area was crowded when the explosion happened at 6:43 p.m. (1643 GMT).
NATO member Turkey faces multiple security threats. As part of a U.S.-led coalition, it is fighting Islamic State in neighboring Syria and Iraq. It is also battling PKK militants in its southeast, where a 2 1/2-year ceasefire collapsed last July, triggering the worst violence since the 1990s.
The U.S. embassy issued a warning on March 11 that there was information regarding a potential attack on government buildings in the Bahcelievler area of Ankara, several kilometers away from the site of Sunday’s blast.
Islamic State militants have carried out at least four bomb attacks on Turkey since June 2015, including a suicide bombing which killed 10 German tourists in the historic heart of Istanbul in January. Local jihadist groups and leftist radicals have also staged attacks in the NATO member country in the past.