JERUSALEM — Israel fired a Patriot missile at an unmanned aircraft that approached the country’s border from Syria for the second time this week, the military said Friday.
The defense system was used to repel a Syrian drone flying over the demilitarized zone, the military said, adding that it was ‘‘most likely intercepted.’’
It said the military will ‘‘operate against attempts to violate the 1974 Separation of Forces Agreement, threats to Israeli sovereignty, and any attempt to harm Israeli civilians.’’ The agreement sets out a demilitarized zone along the frontier and limits the number of forces each side can deploy within 15 miles of the zone.
In a separate development Friday, Gaza’s Health Ministry said a 15-year-old Palestinian was killed by Israeli fire at a border protest.
Thousands of Palestinians gathered near the Gaza border for a weekly protest. Some threw firebombs at Israeli forces from behind the thick black smoke of burning tires. Others flew incendiary kites across the fence.
The Israeli military said Palestinians hurled grenades and explosive devices toward the fence and troops. It said troops saw Palestinians trying to ‘‘breach the security fence and infiltrate into Israel’’ and opened fire.
The Islamic militant group Hamas, which rules Gaza, has led border protests aimed in part at drawing attention to the Israeli-Egyptian blockade imposed after Hamas took control of Gaza in 2007.
On Wednesday, a drone traveled about 6 miles inside Israeli territory before it was shot down.
That incident came as Prime Minister Benjamin Netanyahu visited Moscow for talks with Vladimir Putin about Syria and Iran. Russia has been a key ally of the Syrian government in its civil war.
Israel’s main concern is keeping archenemy Iran, an Assad ally, as far away from its border as possible, along with its proxy, the militia of Lebanon’s Hezbollah.