Occupied Jerusalem: The Israeli military said it struck and destroyed an anti-aircraft battery deep in Syria on Monday after it had opened fire on Israeli jets flying over Lebanon—the first such incident of Syrian forces targeting Israeli planes since the civil war began in 2011.

Military spokesman Lt. Col. Jonathan Conricus said Israeli planes were flying near the Lebanese-Syrian border when they came under fire. They were not hit and returned to base safely.

In response, Israel hit a Syrian anti-aircraft battery about 50 kilometers east of Damascus and “incapacitated” it, he said.

Russian forces in Syria were notified in real time, Conricus said, adding that Israel holds Syria responsible for any attack from its territory.

Israel has largely stayed out of the fighting in Syria but it has carried out dozens of air strikes on alleged arms shipments bound for Hezbollah militants in Lebanon. It has also occasionally carried out limited reprisals along its frontier with Syria in the Occupied Golan Heights, after spillover of Syria’s fighting.

But such a strike deep in Syrian territory is highly unusual.