Thousands of protesters opposed to Israel's war in Gaza, some carrying Palestinian flags, gathered near the US Capitol yesterday ahead of a speech by Israeli Prime Minister Benjamin Netanyahu to members of Congress.

A stage decked with banners included one declaring the Israeli leader a "Wanted War Criminal" in reference to an arrest warrant sought by International Criminal Court prosecutors.

Oscar-winning actor Susan Sarandon took to the stage and condemned the death toll. "No-one is free until everyone is free," Sarandon said.

Nearby, demonstrators placed nearly 30 human-size cardboard coffins wrapped in Palestinian flags in memory of those killed in the war in Gaza. Traffic was barred from several roads near the Capitol.

"I want all aid (to) be suspended to Israel due to its actions in Gaza," said Bradley Cullinan, who said he traveled to the area from Columbus, Ohio, 400 miles away.

Dozens of Democratic lawmakers planned to skip Netanyahu's speech to Congress, expressing dismay over the thousands of civilian deaths and the humanitarian crisis from Israel's campaign in Gaza.

Members of an ultra-Orthodox Jewish group carried Palestinian flags and signs reading "Free Palestine" and "Anti-Zionism is not antisemitism," while a group of younger protesters danced to Arabic music and carried large banners reading "Stop Arming Israel and "Stop War Crimes in Gaza."

Pro-Palestinian groups and university students have for months protested in the US against Israel's offensive in Gaza, a Hamas-ruled enclave where health authorities say nearly 40,000 Palestinians have been killed and nearly all of its 2.3mn people have been displaced.

ICC prosecutors say there are reasonable grounds to believe Netanyahu and Israeli Defence Minister Yoav Gallant bear criminal responsibility for alleged war crimes and crimes against humanity.