Smoke rises from outside the US embassy in Sanaa, Yemen, after the blasts. (AP)

Sanaa (Yemen), Sept. 17 (AP): Attackers armed with automatic weapons, rocket-propelled grenades and at least one suicide car bomb assaulted the US embassy in the Yemeni capital today.

Sixteen people were killed, including six assailants, officials said. No Americans were hurt in the deadly attempt to breach the compound walls, which the US said bore “all the hallmarks of an al Qaida attack”. The dead included six attackers, six Yemeni guards and four civilians, the state news agency SABA reported. Security officials said people lined up for visas were among those killed or wounded.

Multiple explosions rang out outside the heavily-guarded facility, and gunfire raged for at least 10 minutes at the concrete checkpoints that ring the compound.

It was the deadliest attack on a compound that has been targeted four times in recent years by bombings, mortars and shootings. Yemen, the ancestral homeland of Osama bin Laden, has struggled to put down al Qaida-linked Islamic militants.

Just last month, the state department allowed the return of non-essential personnel and family members who had been ordered to leave after a volley of mortars targeted the embassy. The attack instead hit a girls high school next door, killing a Yemeni security guard and wounding more than a dozen girls.

In today’s attack, gunmen in a vehicle attacked a checkpoint outside the embassy with RPGs and automatic weapons, Yemeni security officials said. During the assault, suicide bombers in a vehicle made it through the checkpoint and hit a second, inner ring of concrete blocks and detonated, the officials said, speaking on condition of anonymity.

“This attack is a reminder that we are at war with extremists who will murder innocent people to achieve their ideological objectives,” President George W. Bush said.

SABA, citing an unidentified interior ministry official, reported that two suicide car bombs detonated and made no mention of a gunbattle. There was no immediate explanation for the differing accounts. A senior US official in Washington said at least five detonations were heard — but embassy officials spoke of “secondary explosions”.