At least four of the Paris attackers were listed in a central counter-terrorism database maintained by the U.S. intelligence community, five U.S. officials said on Thursday. At least one and possibly more of the attackers was also on a more selective U.S. "no fly list",...

ISIS is aggressively pursuing development of chemical weapons, setting up a branch dedicated to research and experiments with the help of scientists from Iraq, Syria and elsewhere in the region, according to Iraqi and U.S. intelligence officials. Their quest raises an alarming scenario for the...

A woman suicide bomber blew herself up in a police raid on Wednesday that sources said had foiled a jihadi plan to hit Paris's business district, days after a wave of attacks killed 129 across the French capital. Police stormed an apartment in the Paris suburb of St. Denis...

Iran has started cutting back on some nuclear technology, which could be reengineered to make nuclear weapons, in line with a deal with six world powers, a U.N. nuclear agency report said Wednesday. However, diplomats familiar with the report cautioned that the country is keeping thousands of...