TEL HAZEKA, Golan Heights — An Israeli tank struck a Syrian army vehicle Monday after a mortar shell landed on Israeli-held territory, the military said, in the first direct confrontation between the countries since the Syrian uprising broke out, sharpening fears that Israel could be drawn into the civil war next door.

Israel has steadfastly tried to avoid getting sucked into the Syrian conflict, but it has grown increasingly worried after a series of mortar shells have struck territory in the Israeli-controlled Golan Heights in recent days. On Sunday, Israel fired a ‘‘warning shot’’ into Syria in response to the shelling.