A car bomb exploded near the US embassy in Yemen Wednesday, witnesses reported.

Two explosions were heard, followed by gunfire, residents of Yemen's capital Sana'a said.

Injured people were taken away in ambulances, they added.

A reporter with al-Arabiya said a fire broke out in the embassy building.

Police sealed of the streets around the embassy quarters in the Sheraton district of Sana'a. There were no immediate reports of casualties.

In a grenade attack carried out by extremists in front of the US embassy in March 2007, one Yemeni police officer was killed.

Three police officers and four girls in a neighbouring school were injured.

Al-Qaeda terrorists attacked USS Cole in the Gulf of Aden in 2000, killing 17 marines.