Two militants riding a motorcycle blew themselves up in front of the U.S. embassy in Tunisia's capital, Tunis, on Friday, killing a police officer and injuring several others, according to local media.

The country's Interior Ministry said the two militants were killed carrying out the attack and five police officers were injured, as well as a civilian.

But state news agency TAP said one policeman was killed.

The identities of the militants were not immediately known and their motive remains unclear. 

The U.S. embassy earlier confirmed the attack in a tweet, saying emergency personnel are responding to an explosion near the embassy and urged people to avoid the area.

It has not so far revealed if there's any damage to the embassy.

(Cover: A cordon of riot police officers guard the US embassy in Tunis, Friday, Sept. 14, 2012./ AP)