Russian fighter jets have targeted a weapons depot in Syria’s terrorist-held Idlib province, as part of the Syrian government’s ongoing battle to retake the last bastion of foreign-backed militants in the country.

Russia’s defense ministry announced on Wednesday that the warehouse belonged to the Hayat Tahrir al-Sham (HTS) terrorist group.

According to the statement carried by Russia’s RIA news agency, the HTS had been using the building to store drones and other weapons in anticipation of a planned attack on the Russian air base at Hmeimim, in the western province of Latakia.

A ministry official told RIA that Moscow ordered the airstrike after receiving a tip about the delivery of a large number of drones to the depot.

After purging terrorists from most parts of the country thanks to support from Iran and Russia, Syria has been preparing for an offensive on Idlib to free the city.

It was reported in January that the Syrian army had dispatched military equipment, including artillery, armored vehicles and personnel carriers, to the outskirts of the western provinces of Hama and Idlib.

However, Damascus had to shelve those plans after Russia and Turkey brokered a cease-fire in September to prevent attacks on the city.

Russia said the Wednesday attack was coordinated with Turkey, which has been trying to avert a Syrian offensive against the city near its borders.