WAS IT too optimist too fast to judge terrorism over in Saudi Arabia? While it might yet be brought under control, events this week show it gaining in sophistication. This week, Saudi Arabia stood witness to two operations: the first, a failed suicide attack against a massive oil processing plant at Abqaiq, the second, the hunting of alleged militants in Riyadh. Indeed, terrorist successes have been few and far between over the past year. This, however, could be attributed either to the successes of the security apparatus in the kingdom or the involvement of militants fighting in neighbouring Iraq. Regardless of the true reason, there's no doubt Saudi Arabia remains a target for Al-Qaeda. In terms of security apparatus successes, Saudi security forces have killed more than 100 militants in the last year, including the alleged leader of the Saudi branch of Al-Qaeda. Authorities also claim to have made progress in discouraging and preventing the recruitment of young men to the militant cause. On Monday, security forces killed five suspected militants in two simultaneous raids in the Saudi capital Riyadh. According to security sources, a siege took place at a villa in a Riyadh suburb in which shots were fired and grenades thrown. The Saudi Interior Ministry said one other suspect had been arrested elsewhere in the capital. The Riyadh operation followed Friday's attempt by militants to carry out a suicide bomb attack at the largest oil processing plant in eastern Saudi Arabia. The attack at Abqaiq was foiled when guards opened fire on cars carrying explosives as they tried to ram perimeter gates. At least one of the vehicles blew up, killing the occupants. Two guards were also killed, and another two wounded. An Interior Ministry statement said the two bombers killed were on a list of the 15 most wanted Al-Qaeda-linked terrorists issued by Saudi authorities last June. A Web site frequently used by Islamic militants said Al-Qaeda network was responsible for the attack on Abqaiq, although the claim could not be verified. According to Al-Qaeda logic, the operation was "part of the project to rid the Arabian Peninsula of infidels," and was intended to stop the "pillage of oil wealth" from Muslims. True or not, what is definite is that the attack was the first direct assault on Saudi oil production. Saudi officials, nonetheless, insist this is the last gasp of a movement that the state has done everything to erase, through strong policing, good intelligence and stringent efforts to curb the ideology that produces Islamic militancy. For many, Saudi assurances sound too good to be true.