The rocket attack on a British embassy convoy in Sanaa on Wednesday "had all the hallmarks of al- Qaida," the Yemeni Interior Ministry said in a statement posted on its website.

The ministry said the rocket damaged the rear of the staff's car en-route to the British embassy and slightly injured one of the staff, while others survived the attack unharmed.

"Police are tracking down the perpetrators of this crime," the ministry added.

Also on Wednesday, British Foreign Secretary William Hague, in a statement, described the attack as "shameful," saying "this shameful attack on British diplomats will only redouble Britain's determination to work with the government of Yemen to address the challenges the country faces."

Earlier on Wednesday, a security official of the Yemeni Interior Ministry told Xinhua that a convoy of the British embassy in the capital Sanaa was attacked by a rocket-propelled grenade ( RPG) fired by gunmen, three bystanders died and several embassy staff injured.

However, a source at the British embassy told Xinhua that five of the British staff were seriously injured, adding the embassy has been closed.

"The five injured were sent to the hospital after their car was seriously damaged," the unnamed source said.

All roads leading to the British embassy in Sanaa had been closed and the area where the attack took place was cordoned off by the police.

The attack is the second of its kind against the British staff in the Yemeni capital of Sanaa. On April 26, an al-Qaida suicide bomber threw himself at the convoy of British ambassador to Yemen in Sanaa. The attack only left the bomber dead and three passersby injured while the diplomat and his escort survived unscathed.

A month later, the Yemen-based al-Qaida group claimed responsibility for the attack.

Only two days before Wednesday's attack, the Yemeni Interior Ministry announced it would step up security around foreign establishments in Sanaa.

Yemen, the ancestral homeland of al-Qaida network leader Osama bin Laden, intensified security operations and air raids against terrorist groups, after the Yemen-based al-Qaida wing claimed responsibility for a botched Christmas Day attempt to blow up a U. S. plane bound for Detroit.