Tens of thousands of Israelis protested against Prime Minister Benjamin Netanyahu on Saturday as Israel's war against Hamas in Gaza reaches its half-year mark.

Organisers said about 100,000 people converged at a Tel Aviv crossroads renamed "Democracy Square" since mass protests against controversial judicial reforms last year.

Chanting "elections now," protesters called for his resignation as the war in Gaza enters its seventh month on Sunday.

Rallies were also held in other cities, with Israel's opposition leader Yair Lapid taking part in one in Kfar Saba ahead of his departure for talks in Washington.

"They haven't learnt anything, they haven't changed," he said at that rally.

"Until we send them home, they won't give this country a chance to move forward."

Israeli media said clashes had broken out between protesters and police at the Tel Aviv rally and police said one protester had been arrested.

Later, the protesters in Tel Aviv were joined by families of Gaza hostages and their supporters.

Earlier, the army announced that troops had recovered the body of a hostage abducted by Palestinian militants during the October 7 attack and later murdered in captivity in the Gaza Strip.

The recovery of Elad Katzir's body brings to 12 the number of bodies of hostages which the army says it has brought home from Gaza during the war.

The Hamas attack resulted in the deaths of 1,170 people in southern Israel, most of them civilians, according to Israeli figures.

Israel's retaliatory offensive against Hamas has killed at least 33,137 people in Gaza, mostly women and children, according to the health ministry in the Hamas-run territory.

About 250 Israelis and foreigners were taken hostage by militants on October 7.

The army says 129 are still being held in Gaza, including 34 who are presumed dead.

Demonstrators are to take to the streets again on Sunday, with a rally planned in Jerusalem. (AFP)