Yemeni security officials were warned about a possible Al Qaeda attack, but said Tuesday they did not think it would include the suicide bombing that killed a group of Spanish tourists visiting a remote temple.

A regional official blamed the terrorist group for Monday's attack, which killed seven Spaniards and two Yemenis at the temple linked to the ancient Queen of Sheba. Governor Arief al-Zoka said the "security apparatus are chasing the plotters" and that "Al Qaeda is behind it."

One of six injured survivors told a Spanish radio station Tuesday the scene was a "nightmare."

"I climbed out of the window. I saw that the first car was burning, in the second one, the people looked pretty bad and in mine, everyone was shouting," Maria BegoIna Larrabeiti told Onda Cero Radio from Althura Hospital in the Yemeni capital of San'a.

"Then I couldn't see what was happening in the fourth as I ducked because they were shooting," she added. "It was an absolute nightmare."

The vehicles carrying the tourists were shredded almost beyond recognition, with human remains scattered along with women's clothing, a bag, shoes, and picnic items.

A security official said Al Qaeda had warned recently of attacks against Yemeni oil facilities, government institutions and foreign embassies. Security was heightened at those places, said the official, speaking on condition of anonymity because he was not authorized to speak to the media.

"What happened yesterday was unexpected," the official said. "They managed to mislead us."

Yemeni President Ali Abdullah Saleh offered a $76,000 reward for information about those behind the attack, which occurred in the central province of Marib, an area known for lawlessness and Al Qaeda sympathies. Spain and the United States have warned against travel to the area, where foreigners have been frequently kidnapped.

The U.S. Embassy banned its employees from leaving San'a, and canceled its July 4 celebrations. It urged Americans in Yemen to "keep a low profile."

Spain's Foreign Minister Miguel Angel Moratinos said Yemen believed the attack was directed against the country's tourist sector and not against Spain. Spain has sent a medical plane with doctors and police specialists to Yemen to bring back the injured and the bodies of the dead.

"We're all in a lot of pain. That's all we can say at the moment," said a woman who answered the phone at the Barcelona home of one of those killed, Gabriel Tortosa Ortega. It was not immediately possible to obtain her name.

The attack occurred the same day a trial ended in Madrid of 28 people, mostly Moroccan, for the 2004 Madrid train bombings blamed on Al Qaeda that killed 191 people and injured some 1,500.

Witnesses said a car drove into the tourists near the 3,000-year-old temple, known by its Arabic name, Balqis. A group of teens said they heard gunshots before the attack. Other witnesses said the car with the bomber was parked and blew up when the tourists approached.

According to the security official, Al Qaeda was responsible for the killing of one senior provincial official two months ago. A number of known Al Qaeda operatives remain at large in Yemen.

Yemen is the ancestral home of Usama bin Laden, and the Marib region is home to four powerful tribes with more than 70 branches and is known to be a hotbed of support for Al Qaeda.

About 100 foreigners have been kidnapped in the area since the 1990s. Tourists are a rare sight, though more have been visiting lately.