Yemeni authorities have arrested dozens of people with suspected links to a suicide bombing that killed seven Spanish tourists and two Yemenis two days ago, security sources have said.

Ali Abdullah Saleh, the Yemeni president, and senior officials have suggested the group was behind the car bomb at the Queen of Sheba Temple on Monday.

"Tens of suspects who we believe have links to al-Qaeda have been arrested in three regions, Sanaa, Abyan and Aden," one official said.

A security source said on Monday that the bomber may be one of 13 convicted al-Qaeda members who escaped from prison in 2006, but Saleh said earlier that evidence so far indicated he was a non-Yemeni Arab.

Convoy attacked

The bomber crashed a car packed with explosives into the tourists' convoy as they were ending a tour of the archaeological site, which dates back 3,000 years to the time of the biblical Queen of Sheba, 150km from Sanaa.

Saleh has admitted that security services had been warned last week of an impending attack but did not know where or when it would take place.

"Security measures were taken around sensitive sites such as oil installations but we did not think of this temple," he said.

Yemen has been trying to attract tourist revenues to the impoverished country by promoting the temple as a major attraction.

"This incident is a blow to the national economy and will affect tourism, but should not affect investment," Saleh said.

Bodies returned

The remains of the three men and four women killed in the attack were returned to Spain on Tuesday. Five wounded people also returned.

Security sources said the attack came after al-Qaeda released a statement demanding the release of some of its members jailed in Yemen and threatening to take unspecified action.

"Preliminary information indicates that the al-Qaeda organization is behind the cowardly attack," an interior ministry official told the state news agency on Monday.

Yemen has been fighting a domestic organization linked to al-Qaeda which includes people on a "most-wanted" list issued by the US.

PHOTO CAPTION

People gather around the aftermath of the explosion in Yemen