A small bomb exploded near the Turkish prime ministry building in the capital Ankara on Monday, about an hour before a cabinet meeting was due to be held there, and one person was slightly injured, officials said.
Police closed off the area where the explosion took place, at the entrance to a car park for both the prime ministry and the Appeals Court. Police described it as a percussion bomb, a device which makes a loud noise, but causes little damage.
It is understood that the explosive material was 150 grams (5.2 ounces) of light explosives placed inside a plastic bottle, Ankara Governor Alaadin Yuksel told reporters.
Asked how such an attack could have happened at high security area of the capital, he said: We are examining everything. Our colleagues are examining the camera recordings.
The blast follows a remote-controlled bomb attack in Istanbul Thursday last week which wounded 15 policemen and one civilian.
Kurdish separatists, Islamist militants - including al Qaeda - as well as groups on the far left and right have all carried out bomb attacks in Turkey, but there was no immediate claim of responsibility for the blast.
A group connected to the separatist militant Kurdistan Workers Party (PKK) claimed responsibility for a car bomb that killed three people in Ankara in September and threatened more attacks on Turkish cities.
The Kurdistan Freedom Hawks (TAK) said at the time the capital was the beginning of a series of attacks and said it was behind a previous attack in Antalya, on the Mediterranean coast, where several tourists were wounded by a small explosion on a beach.
(Writing by Jon Hemming Editing by Maria Golovnina)