Picture shows the devastated Al-Hamra expatriate housing compound in Riyadh after it was hit by a car bombing

RIYADH, May 14 (IslamOnline.net & News Agencies) - The United States ordered non-essential U.S. diplomats and the families of all its embassy and consulate personnel to leave Saudi Arabia amid conflicting reports on the death toll of the triple bombing attacks which had rocked the capital Riyadh late Monday, May 12.

The draw-down in the U.S. diplomatic presence in Saudi Arabia reflects grave fears of ongoing threats in the country, the State Department said Wednesday, May 14, in a statement that renewed an existing travel warning for the country.

“U.S. citizens are reminded of increased security concerns and the potential of further terrorist attacks in Saudi Arabia,” the department said.

The Saudi Interior Ministry said late Tuesday that at least 29 people were killed, including nine “suicide bombers” and seven Americans, in the bombing attacks, while State Department officials, and later, U.S. Vice President Dick Cheney said that more than 90 people had died, including up to 12 Americans.

U.S. Secretary of State Colin Powell, touring one of the bombed sites, stressed Tuesday the attacks bore "all the fingerprints" of the al-Qaeda, also blamed for the September 11, 2001 strikes on New York and Washington.

“It was very well executed and it shows the nature of the enemy we are working against,” he said during a tour of a devastated compound housing personnel of U.S. firm Vinnell.

FBI Step In

A team of investigators from the U.S. Federal Bureau of Investigation (FBI) have been dispatched to Saudi Arabia to help with the probe into who carried out the attacks, the BBC News Online reported Wednesday.

The FBI "assessment team" is led by a senior official from the counterterrorism division and includes up to a dozen agents and technicians.

Meanwhile, a high-ranking U.S. official said Tuesday, after Powell's visit to Saudi Arabia, that the bombings were executed like true commando operations.

In one of the attacks, bombers took “thirty seconds to a minute” to knock out the security post at the compound housing the Vinnell Corporation's employees, the official told reporters on condition of anonymity.

From within a Ford sedan, they started by killing or wounding security guards sitting in a vehicle equipped with a machine gun, then seized control of the guard post to allow a booby-trapped Dodge Ram truck through the compound's gate.

The use of U.S.-made cars ensured that the bombers attracted little attention as they approached the compound, the official said.

“Once the gate was open, the shooters went in” and opened fire “and the truck came in,” he added.

The assailants then drove the truck into a corner best placed to maximize the effects of a blast, next to a four-storey building housing mainly unmarried employees, and triggered the explosives.

“The building took the major shock wave. If they had done it at the intersection, the blast would have gone up the streets,” the U.S. official explained.

According to a senior U.S. military officer at the site, the three attacks occurred at practically the same time and followed the same scenario, with one vehicle attacking the guard post at the compound's entrance to allow the second vehicle access.

U.S. officials said the explosives used were most likely of the RDX type, which make little noise but produces a massive shock wave.