Car bomb in Yenem’s southern port city of Aden kills at least nine soldiers and wounds 21 others

A suicide bomber drove a booby-trapped car into an army checkpoint outside Yemen's southern port city of Aden on Sunday, killing at least nine soldiers and wounding 21 others.

The attack, which the government blamed on Al-Qaeda's Yemen-based wing, comes weeks after the army deployed security forces to surround the coastal city, which lies east of a shipping strait where some 3 million barrels of oil pass daily.

The military has been trying to stop militants from slipping into Aden, after they seized several areas in the neighboring province of Abyan in recent months and presented a rising challenge to military control.

Unrest in the south has erupted as mass protests seeking to end President Ali Abdullah Saleh's 33-year rule drag into a sixth month, setting off sporadic clashes across the fractious and impoverished country. Saleh is convalescing in Riyadh after a bomb blast in his presidential compound in June.

The Defense Ministry said the attacker, who was also killed in the explosion, hit a convoy at the checkpoint that had been headed to reinforce a military offensive on Abyan's provincial capital of Zinjibar, which the army has been trying to recapture from militants for over a week.

"The suicide attack by al Qaeda hit a convoy headed to Abyan ... the attacker died and his limbs were scattered around the area," the ministry said in a mobile phone message sent to journalists in Yemen.

The blast comes days after a car rigged with explosives blew up and killed a British ship surveyor in Aden, which officials said was a targeted attack against the long-time resident.

Witnesses to the checkpoint attack on Sunday said they saw a car speed into a street cordoned off by armored vehicles. It blew up, setting at least two of the vehicles ablaze as a cloud of smoke spread over the area. "The car crashed into a military armored vehicle, which exploded and caught fire. The soldiers started shooting heavily," a witness said.

Security analyst Theodore Karasik, of the Dubai-based INEGMA group, said the style of the attack suggested al Qaeda was behind it. "This has all the hallmarks of al Qaeda ... They (the convoy) were preparing to go to Abyan to join the fighting so this is an al Qaeda tactic to interrupt the flow of soldiers to that area," he was quoted by Reuters as saying.

A military source told Reuters the Sunday attack would not deter the offensive in Abyan, in which dozens have been killed or wounded and little territory regained. "The attack won't stop the armed forces from going after the terrorists in Abyan," he said.