A powerful bomb explosion wounded at least 15 people in the center of the Turkish capital Ankara on Tuesday, a government official said.
"There are no dead. Fifteen people were injured," Deputy Prime Minister Besir Atalay was quoted as saying by the Anatolia news agency.
Another government official said a bomb caused the blast.
"There has been information that the blast was caused by a bomb," Bülent Arinc, who is also deputy premier, was quoted as saying by the private NTV television.
The Ankara governor, however, refrained from associating the blast with an attack, adding that there was an ongoing investigation.
"Technical teams are on the ground and listening to the witnesses," Governor Alaaddin Yuksel told Anatolia.
One witness at the scene said a gas tube at a shop nearby was thrown outside and caused a car explosion, according to the governor.
The blast, which occured near the Cankaya district administration offices, blew out windows of shops and offices in the surrounding area, damaged cars and sparked a fire which was later put out by firefighters at the scene, NTV said.
The offices are near downtown Kizilay square in Ankara, a city of 4 million inhabitants and home to many government buildings as well as military headquarters.
Police feared a second explosion and sealed off the area, said NTV.
Kurdish rebels have conducted bomb attacks in Turkey's urban areas in the past.
The blast comes at a time when Turkish officials threatened to launch an incursion by its ground forces against Kurdish rebel bases operating in northern Iraq after a recent spate of attacks.
Speaking to Turkish daily Hurriyet last week, Prime Minister Recep Tayyip Erdogan said those were matters not to be discussed but to be acted upon.
Turkey's government has been considering a series of measures in the face of the upsurge in attacks, including a request to parliament to extend its authorisation for cross-border military operations for one more year after it expires next month.
Turkish aircraft have repeatedly bombed the bases of the Kurdistan Workers' Party (PKK) in northern Iraq since August 17, and more than a 100 rebels have been killed in the raids, according to official figures.
The PKK, listed as a terrorist group by Ankara and much of the international community, took up arms in Kurdish-majority southeast Turkey in 1984, sparking a conflict that has claimed about 45,000 lives.