Russian military intelligence has exposed an Islamic State plan to mount a major attack on the city of Deir ez-Zor in Syria, the Russian Defense Ministry said. It added that preemptive strikes to prevent the attack resulted in some 180 terrorists killed, including two commanders.

The concentration of Islamic State (IS, formerly ISIS/ISIL) forces near the besieged Syrian city was noticed by Russian surveillance drones in early June, the ministry said in a statement on Saturday.

The military command decided to conduct preemptive airstrikes to prevent their ensuing attack.

Two airstrikes delivered on June 6 and 8 by the Russian Air Force in Syria killed two prominent IS field commanders, Belgian Abu Umar al-Beljiki and Egyptian Abu Yasin al-Masri, the statement said.

Image of area hit by airstrike that may have killed #ISIS leader published by Russian MoD https://t.co/OiW42bhpat — RT (@RT_com) June 16, 2017

In addition, 180 jihadist fighters were killed and 18 vehicles of their vehicles were destroyed. IS also lost an artillery piece and an ammunition stockpile, according to the statement.