At least two people have died in a suicide bomb attack at the entrance of the US Embassy in the Turkish capital Ankara, police say.
An Associated Press journalist saw a body in the street in front of an embassy side entrance.
The bomb appeared to have exploded inside the security checkpoint at the entrance of the embassy.
Private NTV television said two security guards at the entrance were killed.
Several ambulances were dispatched to the area. At least one woman who appeared to be seriously injured was carried into an ambulance.
The embassy building is heavily protected. It is near an area where several other embassies, including those of Germany and France, are located. Police sealed off the area and journalists were being kept away.
There was no claim of responsibility, but Kurdish rebels and Islamic militants are active in Turkey. Kurdish rebels, who are fighting for autonomy in the Kurdish-dominated south-east, have dramatically stepped up attacks in Turkey over the last year.
Homegrown Islamic militants tied to al Qaida have carried out suicide bombings in Istanbul, killing 58, in 2003. The targets were the British consulate, a British bank and two synagogues.
In 2008, an attack blamed on al Qaida-affiliated militants outside the US Consulate in Istanbul left three attackers and three policemen dead.