SEVEN Spanish tourists and two Yemeni drivers were killed today when a suicide bomber rammed his explosives-laden car into their convoy at an ancient temple in Yemen, officials said.

The interior ministry said the bombing in the restive northeastern region of Marib appeared to be the work of the al-Qaeda network.

"Preliminary information indicates that the al-Qaeda organisation is behind the cowardly attack, " an interior ministry official told the Saba news agency.

"This criminal attack has killed seven Spanish tourists and two Yemeni nationals who worked as drivers and tourist guides, and wounded six Spanish tourists and two (Yemeni) nationals."

It was one of the deadliest bombings targeting foreigners in Yemen, the ancestral homeland of al-Qaeda leader Osama bin Laden which has been battling a number of attacks by the network in recent years.

Witnesses said the attack occurred as the tourists were wrapping up a tour of a temple in Marib which dates back 3000 years to the time of the biblical Queen of Sheba.

There was no immediate claim of responsibility.

The security official said on the website of the Yemeni defence ministry's newspaper that the bomber slammed his explosives-laden vehicle into the tourists' five-car convoy, which included a police car.

Tribal sources said the bomb was heard as far as 20km away from the site of attack, near the Mahram Bilquis, or temple of the moon god.

Yemen has faced a wave of Islamist unrest among its Sunni Muslim majority which it has been fighting with help from US special forces based over the Bab al-Mandab strait in Djibouti.

Thirty-six Yemenis are currently on trial charged with planning and carrying out attacks for al-Qaeda but several are on the run after tunnelling out of a Sanaa prison in February last year and are being tried in absentia.

Last month, a soldier with "emotional problems" opened fire on oil workers with US energy giant Occidental Petroleum killing an Indian woman engineer and wounding six other people, including the local American boss, in the eastern Shabwah province.

Yemen, which has 20 million inhabitants, is one of the world's poorest countries, despite its proximity to oil-rich Saudi Arabia.