The US Middle East Command unexpectedly announced strikes on nine targets in two areas of Syria linked to Iranian-backed forces, in response to recent attacks on US troops in the past 24 hours.

The strikes are aimed at reducing the ability of Iranian-backed groups to plan and carry out attacks against U.S. forces and their coalition allies in Syria and Iraq as part of the counterterrorism mission, Central Command officials said. The top U.S. commander in the region, Gen. Michael Kurilla, said any attacks on American troops would be met with a tough response.

Military analysts note that claims of such strikes have been extremely rare in recent years, although attacks on American bases in the Middle East occur regularly, often using kamikaze drones.