Authorities in Azerbaijan have arrested 26 citizens of the former Soviet nation accused of joining militant groups in Syria, including the Islamic State one.

Azerbaijan's National Security Ministry said in a statement Tuesday that those arrested have been accused of involvement in illegally armed groups, trafficking of weapons and explosives, and other charges that could carry life imprisonment. The suspects have been taken into custody after returning to Azerbaijan, but the ministry didn't say when the arrests were made.

The statement followed a wave of airstrikes launched Monday and early Tuesday by the U.S. and five Arab allies against Islamic State targets in eastern Syria.

Azerbaijan, a mostly Muslim energy-rich Caspian Sea nation, has been a staunch U.S. ally, having contributing troops to the U.S.-led missions in Afghanistan and Iraq.