JERUSALEM — An Israeli-American agitator who has pushed for more Jewish access and rights at a hotly contested religious site in Jerusalem was shot and seriously wounded Wednesday night by an unidentified assailant in an apparent assassination attempt.

The shooting of the activist, Yehuda Glick, compounded fears of further violence in the increasingly polarized holy city, where tensions are already high over fears of a new Palestinian uprising against Israeli occupation.

Reports that Mr. Glick had been shot came as the United Nations Security Council convened in an emergency session, at the request of Palestinian and Jordanian diplomats, to address the religious strife and growing anger over Israeli housing expansions in East Jerusalem, which the Palestinians regard as the capital of a future state.

Israel, which regards all of Jerusalem as its capital, has faced intense criticism over the housing expansions, including from its most important ally, the United States, which has described them as illegitimate obstructions to an any hope for a peaceful solution to the longstanding Palestinian-Israeli conflict.