BEIRUT — For the second time in a week, a suicide bomber targeted U.S. forces in Syria. On Monday, a car drove toward a joint U.S.-Kurdish convoy and exploded 11 yards from a checkpoint in the country’s northeast.

There were no American casualties, according to a statement from the U.S.-led coalition. One Kurdish policeman was lightly injured, according to a statement from the Kurdish-led militia group.

The attack near the town of Shadadi came as the United States began to draw down its presence in Syria and other countries stepped up their activity there. Israel launched a multipronged attack on military targets in Syria late Sunday, several hours after its air defense system intercepted a missile launched at a ski slope crowded with winter revelers.

Israeli authorities said the missile was launched by Iranian troops stationed in Syria. It appeared to be a response to an earlier bombing of an airport south of Damascus that was attributed to Israel.

Meanwhile, the Turkish army and the Syrian rebels associated with it, as well as Russian-backed Syrian government troops and Islamic State, all appear poised to take advantage of a U.S. drawdown. Monday’s hit underscored Syria’s continuing instability, with a multitude of forces vying for control.

Amaq, an agency affiliated with Islamic State, confirmed that a “martyrdom-seeker” had targeted the joint U.S.-Kurdish convoy. It did not elaborate.

The bombing followed one Wednesday that was the deadliest attack on U.S. forces since their entry into Syria. An Islamic State suicide bomber walked into a restaurant in the Kurdish-controlled city of Manbij where U.S. coalition forces and Kurdish militiamen were eating lunch.

He detonated his vest, killing four Americans — two soldiers and two contractors — along with five Kurdish civilians and a number of militiamen.

The U.S. heads a coalition of countries against Islamic State and has worked with Syrian Kurdish fighters to claw back wide swaths of territory that make up what the group called its caliphate.

The Kurds, meanwhile, have leveraged that support and their military victories to administer areas abandoned by the state in Damascus. U.S. officials tout them as a viable alternative to the rule of Syrian President Bashar Assad.

But that arrangement appears to be coming to an end, following President Donald Trump’s repeated statements that he would withdraw from Syria and leave the objective of fighting Islamic State to Turkey. He has said that Islamic State is defeated, although others in his administration acknowledge that the organization remains lethal, if significantly degraded.

Trump has been unclear regarding the timing of such a withdrawal, but any pullout by U.S. forces would probably doom the Kurds’ long-term project.