A suspected Al-Qaeda suicide bomber Sunday killed 12 soldiers and a civilian in an attack on a military base in southeast Yemen, officials said, as government forces pursued extremists in three restive provinces.

A suspected Al-Qaeda suicide bomber Sunday killed 12 soldiers and a civilian in an attack on a military base in southeast Yemen, officials said, as government forces pursued extremists in three restive provinces.

The bombing came just hours after three gunmen were killed when they attacked a checkpoint close to the presidential palace in the capital Sanaa, the same post where five soldiers died on Friday in a similar attack.  

The two attacks appeared to be in reprisal for an army offensive against Al-Qaeda in the Arabian Peninsula in the contiguous provinces of Shabwa and Abyan, in the south, and Baida in the centre, which has been underway since April 29.

The bomber rammed an explosives-laden car into the military police base in Mukalla, the Hadramawt provincial capital, a security official said, adding that the assailant detonated his explosives next to a barracks.

The attack killed 12 soldiers, the military source said, while a medic said civilian succumbed to wounds sustained in the explosion.

"The suicide bomber belonged to Al-Qaeda," said the military source, without giving further information.

In Sanaa, a dawn attack by "terrorists" on a presidential guard checkpoint at Misbahi roundabout ended in the deaths of three gunmen and a civilian, the interior ministry said.

Authorities use the term "terrorists" to refer to Al-Qaeda militants in the impoverished Arab country.

Sanaa has been on alert for days, with tensions spiking after troops entered Azzan, an extremist bastion in southern Shabwa province, prompting the