BAKU, Azerbaijan (AP) — Authorities in Azerbaijan said Tuesday they have arrested 26 citizens of the ex-Soviet nation accused of joining militants in Syria, including the Islamic State group.

Azerbaijan, a staunch U.S. ally, announced the arrests hours after the U.S. and its Arab allies launched a series of airstrikes against Islamic State targets in eastern Syria.

Azerbaijan's National Security Ministry said in a statement 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 ministry detailed the case of one suspect, Elshan Gurbanly, saying that he was accused of moving to Syria via Turkey earlier this year to join IS. It said Gurbanly was wounded in fighting in Iraq in August 2014.

The ministry said that another suspect encouraged his 15-year old son to go to Syria to join the militants, which he did. The ministry said that the official investigation is under way, adding that it was searching for other suspects.

Local media have reported that more than 100 Azerbaijani citizens have been killed while fighting alongside militants in Syria, but there has been no official information about how many Azerbaijanis have gone there and how many of them have died.

Azerbaijan, a mostly Muslim energy-rich Caspian Sea nation, has maintained close ties with Washington and contributed troops to the U.S.-led missions in Afghanistan and Iraq.