Russia's defense ministry says it has killed several leaders of the Islamic State group outside their stronghold of Raqqa in Syria.<br />The ministry said Wednesday that it received a tip-off from the Syrian opposition last week about an upcoming meeting of IS leaders outside Raqqa, and kept the area under surveillance for two days before an Su-34 bomber attacked the meeting place.<br />The defense ministry said it is cooperating with unidentified "representatives of patriotic opposition forces" who have been providing Moscow with potential targets in Syria.<br />Russia is a staunch ally of President Bashar Assad, and it has been accused of using its air force operation in Syria which began in September in order to prop up Assad.
