JERUSALEM (Reuters) - Israel’s military said it had fired a missile at a drone that approached from Syria on Friday, and a witness on the Syrian side of the frontier said the aircraft had been brought down.

The incident occurred two days after an Israeli Patriot missile downed what the Israeli military said was a pilotless and apparently unarmed Syrian reconnaissance aircraft near the Sea of Galilee in northern Israel.

“A Patriot missile of the IDF’s (Israel Defence Forces)aerial defense system was launched toward a Syrian UAV flying over the demilitarized zone. The UAV was most likely intercepted,” the military said in a statement.

A witness on the Syrian side of the Golan Heights frontier said the aircraft had crashed.

Israel has been on alert as Syrian President Bashar al-Assad’s forces advance on rebels in the vicinity of the Golan Heights, much of which Israel captured from Syria in 1967 and annexed, in a move not recognized internationally.

Israel worries that Assad could let his Iranian and Lebanese Hezbollah reinforcements entrench near Israeli lines, or that Syrian forces may defy a 1974 Golan disengagement agreement.