ANKARA, Turkey (AP) — Two Turkish soldiers were killed Thursday in a rocket attack in Syria's northwestern Idlib province, Turkey's Defense Ministry said.

A ministry statement said a third soldier was wounded in the attack, which it said was carried out by "radical groups."

Turkey's artillery units immediately mounted a powerful retaliation, the ministry said, but did not provide further details.

The attack comes two weeks after Turkey and Russia — which support opposing sides in the Syria conflict — agreed to a cease-fire in Idlib, halting a three-month air and ground campaign by the Syrian government in the rebel-held province.

The offensive killed hundreds and sent 1 million people fleeing toward the Turkish border. It also resulted in rare direct clashes between the Turkish military and Syrian government troops. Some 60 Turkish soldiers have been killed in Idlib since the start of February.

The Turkish defense statement did not identify the group it holds responsible for the attack.