The director of the International Atomic Energy Agency, Muhammad el-Baradei, warned yesterday that the events of Sept. 11 have increased concerns that terrorists might try to fashion nuclear weapons or launch attacks directly against nuclear facilities. El-Baradei’s remarks came one day after the U.S. restricted airspace around all nuclear power plants due to security concerns, and just prior to a conference in Vienna on safeguarding against nuclear terrorism. The remarks were directed at the five acknowledged nuclear powers, as well as at India, Israel, and Pakistan, all of which are believed to have nuclear capabilities. Pakistan recently detained three atomic scientists for questioning about whether atomic weapons may have been obtained by Osama bin Laden’s Al Qaeda network.