RIYADH, Jan 3: Tons of explosive materials were used in last week's twin suicide bombings in Riyadh, Saudi Arabia's interior ministry said on Monday. The vehicle used in the December 29 attack on the interior ministry building was a car "laden with around 1.5 tons of explosive mixes, including ammonal and other commercial explosives," said a statement carried by the official SPA news agency.

Another car carrying 1.3 tons of "the same explosive mixes" detonated 380 meters (yards) away from the base of the special security forces in eastern Riyadh "after coming under fire from guards at the base," it said.

The ministry has said that five militants carried out the two attacks in which it said no civilians or security men were killed. Monday's statement also identified the third bomber in the attack targeting the ministry as Ismael Ali Mohammad al-Khuzaim, a Saudi.

"He collected information about foreign residents and participated in murdering one of them after kidnapping him," the statement said, in an apparent reference to American aeronautics engineer Paul Johnson, who was abducted and beheaded last June by the so-called "Al-Qaeda in the Arabian peninsula". -AFP