The Saudi Interior Ministry says authorities have arrested 701 suspected al-Qaida-linked terrorists this year, some of them suspected of plotting attacks against the kingdom's oil and economic installations. A statement from the ministry says that of those arrested, 181 were released because there was no proof linking them to the terror network. It says 520 remain in custody. The statement also says that the militants had planned to revive "criminal activities" in the kingdom and that their leaders were based outside the country. The oil-rich kingdom, which is the birthplace of al-Qaida's leader Osama bin Laden, has been waging a heavy crackdown on the group's militants since a 2003 wave of attacks on foreigners here.