An unknown group targeted the US embassy in Ankara, the capital of Turkey, with an explosive device.  At least two security guards were killed in the explosion and an unknown number of people wounded:

A suspected suicide bomber detonated an explosive device at the entrance of the U.S. Embassy in the Turkish capital on Friday and at least two people are dead, a police official said.

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 visa section of the embassy.

Several ambulances were dispatched to the area. An AP journalist saw at least one woman who appeared to be seriously injured being carried into an ambulance.

Private NTV television said two security guards at the entrance were killed.

No one has yet claimed responsibility for the bombing, and it may not be clear yet exactly what the motive is.  Turkey has active terrorist groups both for radical Islam and Kurdish autonomy, although it’s probably not likely that the latter would target the US.  On the other hand, al-Qaeda and its affiliates usually go for more dramatic attacks, with multiple bombings and better penetration of targets.  The image from CNN shows significant damage to the entrance, but it doesn’t appear that anyone exploited it in a follow-up attack.

CNN is also reporting that this was a suicide-bombing attack.

Update: A bit more from CBS:

CNN’s Turkish service said witnesses had seen the bomber approach the building and enter a gate to the fortified compound. It wasn’t clear whether the bomber entered the building before detonating their explosives.

The switchboard for the U.S. Embassy is operated out of Istanbul. A switchboard operator told CBS News the embassy staff had taken cover following the explosion, explaining why nobody answered phones at the Ankara building.

The U.S. Embassy is located in the heart of Ankara. Photos and video broadcast by Turkish television showed significant damage to a wall and what appeared to be a bullet-proof window in the embassy.

In considering suspects, it might not be too bad to keep this in mind, too:

CBS News senior correspondent John Miller, a former deputy director in the National Intelligence Director’s office, says al Qaeda will be one of the first groups considered as suspect in the attack, but he also notes the recent Israeli airstrike in Syria, for which Damascus and its staunch ally Iran vowed to retaliate. …

“Iran, in terms of retribution, would stack Israel and the U.S. together,” says Miller.

Don’t forget that the US and Germany deployed troops and defensive systems to the Turkey-Syria border after a rocket attack from Syria late last year, too.  That may have angered any number of radical groups, as well as Syria and Iran.

We’ll have more on this as it comes.