TOKYO (Reuters) -United Nations Secretary-General Antonio Guterres on Thursday called for an immediate ceasefire in Gaza, after Israel announced the first steps of an operation to take over Gaza City.

The Hostages and Missing Families Forum, which organized the "Israel on Hold” protests, said that over a million people took part in the demonstrations across the country on Sunday. Per the organization, almost 500,000 protesters gathered in Tel Aviv’s Hostage Square.

Israel has begun the "first stages of the attack on Gaza City" on Wednesday as it plans to call up to 50,000 to 60,000 reservists in order to occupy the city, according to Israel Defense Forces spokesman Eddie Defrin and an Israeli military official.