BAGHDAD, Iraq, Aug. 4 — Tens of thousands of followers of the Shiite cleric Moktada al-Sadr rallied in support of the Lebanese militia Hezbollah on Friday, denouncing Israel and the United States for igniting violence throughout the Middle East.

The protest, the largest of several demonstrations in Iraq since the Israeli-Lebanese conflict began three weeks ago, filled 20 blocks of a wide, squalid boulevard and dozens of side streets in the Shiite-dominated Sadr City section of the capital.

All but a handful of the demonstrators were men, mostly young, wearing white cloth to symbolize funeral shrouds. Some carried guns. Waving Lebanese flags and posters of Hezbollah’s leader, Sheik Hassan Nasrallah, they shook their fists and shouted in unison against what they described as the enemies of all Muslims.

“Hezbollah, beloved, hit Tel Aviv, hit Tel Aviv,” the protestors said. “No, no, no, Israel; no, no, no, America,” they chanted, and finally: “if Americans are strong enough, they should come face us.”