According to the newspaper Asharq Al-Awsat published in London today 26 august 2015, 19 years later, explosions designer of (Alkhobar) arrested by the security of Saudi Arabia … he was hiding in Tehran arrested recently in Beirut and delivered to Saudi Arabia.
November 13, 1996 car bombing in Riyadh led the U.S. forces stationed at Khobar Towers to raise the threat condition to THREATCON CHARLIE. Days after the attack, military commanders briefed soldiers and airmen at Khobar that the U.S. had received anonymous communications from an organization claiming to have carried out the Riyadh attack. The attackers claimed their goal was to get the United States’ military to leave the country, and that Khobar Towers would be attacked next if troop withdrawal did not begin immediately. It was at this time that surveillance and other suspicious activity near the perimeter fences of Khobar Towers was noted by United States Air Force Security Forces; however, the forces were forbidden by the Saudi government to act in any capacity outside the perimeter of the compound, and the surveillance continued with near impunity.
The attackers were reported to have smuggled explosives into Saudi Arabia from Lebanon. Al-Mughassil, Al-Houri, Al-Sayegh, Al-Qassab, and the unidentified Lebanese man bought a large gas tanker truck in early June 1996 in Saudi Arabia. Over a two-week period they converted it into a truck bomb. The group now had about 5,000 pounds of plastic explosives, enough to produce a shaped charge that detonated with the force of at least 20,000 pounds of TNT, according to a later assessment of the Defense Special Weapons Agency. The power of the blast was magnified several ways. The truck itself shaped the charge by directing the blast toward the building. Moreover, the relatively high clearance between the truck and the ground gave it the more lethal characteristics of anair burst.
The three-year investigation led the FBI to conclude that Iranians were involved in the attack. At that time the Clinton administration hoped to open a dialogue with reformist president Khatami, which would be impossible after accusing Iranians of supporting terrorist action. A secret letter, delivered directly to Khatami by Sultan Qaboos of Oman, stated that the United States had evidence of direct Iranian involvement in the act, and demanded that those involved be held responsible for their actions. Khatami refused to begin an investigation and Iranian officials stated that al-Qaeda was responsible for the attack.