Israeli jets struck Iranian targets near the town of Kisweh south west of Damascus, causing loud explosions to be heard in the capital, Syrian media reported late Tuesday night local time.

Social media images showed massive blazes as reports suggested Israel had carried out a preemptive strike against missile stocks and missile launchers just hours after the IDF issued a statement saying it had identified irregular Iranian activity in the area.

“The IDF has detected irregular Iranian activity in Syria and is preparing the civilian population on the Golan Heights accordingly, as well as defensive systems. Any aggression against Israel will be met with a severe response,” an IDF spokesman said earlier in the evening.

IDF officials also instructed municipal authorities in the Golan Heights to open civilian bomb shelters and said the military had deployed in an “expanded defensive posture” to respond to a cross-border attack from Syria. The army also said it would prepare the civilian population on the Golan Heights accordingly.

There were also unconfirmed reports that Israel has begun a limited call up of reservists in the civil defense and air defense battalions.