JEDDAH, Saudi Arabia (Reuters) - Saudi Interior Minister Prince Nayef defended late on Saturday the policy of enticing repentant militants after one tried to assassinate his son, but warned there could be more and worse attacks ahead. A suicide bomber posing as a repentant militant blew himself up in the Jeddah office of security chief Prince Mohammed bin Nayef in the first known attack on a member of the Saudi royal family since Al-Qaeda began a violent campaign in the worlds top oil exporter in 2003. Saudi Arabia issued a list of 85 wanted suspects in February and analysts said many of them were in Yemen, including some who had been returned to Saudi Arabia from US detention in Guantanamo Bay and some who had been through a much-vaunted Saudi militant correction programme. The security efforts and strategy that the country is following for reform will not change, Nayef told businessmen at a gathering in Jeddah, defending the correction programme and efforts to win over militants. This incident will not change this policy by which we open the door for those who repent. Al-Qaeda on Sunday identified the man who tried to kill the security chief on Thursday as Abdullah al-Asiri, a wanted suspect who entered Saudi Arabia from Yemen, and gave details on how he was allowed to get so close to the prince. A statement said Asiri was flown to Jeddah from Najran near the Yemeni border after entering from Yemen to give himself up to the Interior Ministry. The hero martyr on the list of 85 wanted persons Abdullah Hassan Tali al-Asiri, known as Abul-Khair, managed to enter his palace, pass his guards and blow up a package, said a statement on extremist websites attributed to the Qaeda Jihad Organisation in the Arab Peninsula. He managed to get through all the inspections at Najran and Jeddah airports and travelled on his (the princes) private jet, it said, accompanied by a picture of Asiri. It was not possible to verify the statement, which said the Saudi government had a network of spies in Yemen of which the Yemeni government was not aware. The Saudi and Yemeni branches of Al-Qaeda merged early this year to form Al-Qaeda in the Arabian Peninsula. They regrouped in Yemen after a vigorous counter-terrorism campaign led by Prince Mohammed, who is also deputy interior minister, that badly damaged militants in Saudi Arabia. Saudi-owned Al Arabiya TV said Asiri was a 23-year-old Saudi whose brother Ibrahim was also on the wanted list. Prince Nayef predicted there could be more attacks. In this country we are targeted... The situation could change and could intensify, not in terms of the number (of attacks) but rather in their nature, and that is more dangerous. Saudi officials fear militants are finding refuge in lawless swaths of Yemen, whose security forces are stretched by a tribal revolt in the north and separatist unrest in the south. Al Arabiya quoted Yemeni Foreign Minister Abubakr al-Qirbi as saying Asiri travelled to Saudi Arabia from the Yemeni region of Mirib, stating he wanted to hand himself in. Meanwhile, Saudi Arabia has tightened security at oil facilities after the countrys anti-terror chief escaped a suicide attack, guards at Abqaiq, the worlds biggest oil processing plant, said on Sunday. Thursday night we received a call to tighten security measures and car inspection at all gates, one security guard said. Even Aramco employees undergo inspection. Theres a lack of trust as militants disguised in Aramcos cars in 2006 attacked the facility, he added. An Aramco spokesperson was not immediately available to comment. Al-Qaeda leaders have repeatedly called for attacks on oil facilities and Western interests in the Gulf to destabilize US-allied rulers and harm the economies of Western countries by blocking the flow of oil. This (Abqaiq) is a sensitive industrial area... security measures are a must, an Aramco employee said. Saudi government security forces foiled the attack on Abqaiq in 2006. Most Saudi oil is exported from the Gulf via the huge pumping and processing facility at Abqaiq in the mainly Shia Eastern province. Abqaiq handles crude pumped from the giant Ghawar field and ships it off to terminals Ras Tanura the worlds biggest offshore oil loading facility and Juaymah. It also pumps westwards across the kingdom to Red Sea export terminals. When such things happen, police, national guards, Aramco impose stricter measures at facilities... so that means more safety, said a Saudi-based contractor who works with Aramco.