JERUSALEM — Israel clashed with Syrian and Iranian military forces on Saturday in a series of audacious cross-border strikes that could mark a dangerous new phase in Syria’s long civil war.

The confrontations, which threaten to draw Israel more directly into the conflict, began before dawn when Israel intercepted what it said was an Iranian drone that had penetrated its airspace from Syria. The Israeli military then attacked what it called the command-and-control center from which Iran had launched the drone, at a Syrian air base near Palmyra.

On its way back from the mission, one of Israel’s F-16 fighter jets crashed in northern Israel after coming under heavy Syrian antiaircraft fire. It is believed to be the first Israeli plane lost under enemy fire in decades.

That prompted a broad wave of Israeli strikes against a dozen Syrian and Iranian targets in Syrian territory. The Israeli military said it hit eight Syrian targets, including three aerial defense batteries, and four Iranian positions that it described as “part of Iran’s military entrenchment in Syria.”

The events, including Israel’s direct engagement with Iranian forces, threatened to intensify the crisis in Syria and showed the extent to which the country has become a battlefield between Israel and Iran, bitter foes in the region.

“This is indeed a dangerous escalation that raises the specter of direct conflict between Israel and Iran in Syria — a far more serious situation than the drawing of red lines and tit-for-tat exchanges that have occurred before,” said Robert Satloff, executive director of the Washington Institute for Near East Policy.

Forces from Russia, Turkey and the United States are also on the ground in Syria in a war with multiple fronts and multiple factions, including the remnants of the Islamic State and other Islamist militant groups.

In the past week, aircraft from three foreign countries have been brought down in the conflict: the Israeli plane; a Turkish helicopter shot down, also on Saturday, as it attacked Kurdish militias; and a Russian plane over Idlib that was bombing rebel-held territory.

Israel has long warned about the risk of conflict as Iranian forces and their allies, including Hezbollah, the Lebanese militant group militia, have dug in on Syrian territory and approached the boundary with the Israeli-held portion of the Golan Heights. Israel, which considers Iran its most potent enemy in the region, has been lobbying world powers to push these forces from the border areas. Read more at NY Times