Suspected Al Qaeda militants opened fire on a convoy of tourists in a remote desert mountain valley Friday, killing two Belgian women and their Yemeni driver. It was the second recent militant attack on foreign tourists in Yemen, the ancestral homeland of Usama bin Laden.

The victims were traveling in a convoy of at least four vehicles through an ancient, ruin-filled desert valley called Wadi Daw'an in Yemen's eastern Hadramut region when the gunmen attacked, a security official said. Four people were wounded.

Karina Lambert, who survived the attack, said it was carried out by four gunmen hiding behind a pickup truck parked by the road.

"They wanted to kill, that's sure, because after the first bursts of machine-gun fire, they approached the vehicles and fired into the cars," she told Belgium's RTL-TVI television network.

At least 10 suspects have been taken into custody and all roads leading to the province have been cut, said the Yemeni official, who spoke on condition of anonymity because he was not authorized to speak to the media.

The bodies of the two slain Belgians were flown by military transport to San'a Friday night.

Belgian Foreign Minister Karel De Gucht identified one victim as Claudine Van Caille, 65. He declined to identify the other one because the family had not yet been informed.

"We don't have any precise information about the involvement of Islamists, but we have to note that the province of Hadramut is know for its Islamism and its extremist groups," Belgian Foreign Minister Karel De Gucht said.

He said the Foreign Ministry issued a travel warning singling out the region where the attack took place: "We have indicated very clearly that this was a risky business."

Bin Laden's ancestral homeland is located just north of where the attack took place. The area is rich with historical sites and was part of the ancient kingdom of Hadramut that stretched from the southern Arabian Peninsula along the Gulf of Aden east to Oman's Dhofar region.

Tourists often go through the Wadi Daw'an en route to Shibam, an ancient town of mud brick houses, some as high as nine stories.

In July, a suicide bomber in an explosives-packed car attacked tourists visiting a temple linked to the ancient Queen of Sheba in central Yemen, killing eight Spaniards and two Yemenis. Yemeni authorities blamed that attack on an Al Qaeda cell.

An Interior Ministry official, also speaking on condition of anonymity, said Yemeni authorities received e-mail and telephone threats of imminent terrorist attacks over the past two days. The official said Al Qaeda militants were pushing for the release of jailed comrades.

Yemen has long been a center of militant activity, and Al Qaeda continues to have an active presence despite a government crackdown. Al Qaeda was blamed for the 2000 bombing of the USS Cole in Aden that killed 17 American sailors and the attack on a French oil tanker that killed one person two years later.

In February 2006, 23 Al Qaeda militants broke out of a prison in San'a. Six of the escapees have since been killed in clashes and 11 recaptured.

One of those still at large, Qasim al-Raymi, has been accused by Yemeni authorities of involvement in the July suicide bombing against the Spanish tourists. Another, Nasir al-Wuhayshi, was later named in a Web statement as the leader of "Al Qaeda in Yemen."

Yemen also has seen turmoil from unruly tribes in lawless areas of the mountainous, impoverished country. Foreign tourists are frequently kidnapped by tribes seeking to win concessions from the government, either better services or the release of jailed relatives. Most have been released unharmed.