Hundreds of thousands of people have gathered in Israel to call for an end to the Gaza war and a deal to secure the release of hostages held by Hamas.

The largest crowd was seen in Tel Aviv's "Hostages Square" on Sunday, with the organisers saying the government's plans to seize control of Gaza City risked the lives of around 20 hostages still being held by Hamas.

A one-day national strike - part of wider protests - closed roads, offices and universities in some areas. Nearly 40 people were arrested during the day.

Israeli Prime Minister Benjamin Netanyahu criticised the protests, saying they would "harden Hamas's stance" and would only slow down the release of the hostages.

Far-right Israeli minister Bezalel Smotrich also denounced the protests, describing them as a "harmful campaign that plays into the hands of Hamas".

The national strike was demanded by the families of hostages and others opposed to the expansion of the war.

Einav Zangauker, mother of hostage Matan and a leading figure in the Hostage and Missing Families Forum, said the group demanded "a comprehensive and achievable agreement and an end to the war".

"We demand what is rightfully ours - our children," she told the crowd in Tel Aviv. "The Israeli government has transformed a just war into a pointless war."

She was speaking after a video was released of her son.

"My heart burns with longing. My whole heart is scorched because of my Matan. Matan, I, an entire nation, we are doing everything we can for you, for all the hostages," she said.

The protests came a week after Israel's war cabinet voted to occupy Gaza City, the territory's largest city, and displace its population, in a move condemned by the UN Security Council.

Thousands of residents have since fled Gaza City's southern Zeitoun neighbourhood, where days of continuous Israeli bombardment have created a "catastrophic" situation, the city's Hamas-run municipality told the BBC.

At least 40 people were killed by Israeli attacks across the territory on Saturday, Gaza's civil defence agency said.

Hamas said in a statement that Israeli forces had been carrying out a "sustained offensive in the eastern and southern neighbourhoods of Gaza City, particularly in Zeitoun".

The Israeli military said it would begin allowing tents to be brought into Gaza by aid agencies again.

"As part of the preparations to move the population from combat zones to the southern Gaza Strip for their protection, the supply of tents and shelter equipment to Gaza will resume," the Israeli military body Cogat said.

Israel plans to forcibly displace a million people from Gaza City to camps in the south but it has not provided an exact timetable of when its forces would enter Gaza City.

Israeli Prime Minister Benjamin Netanyahu is reported to want the entire city under Israeli occupation from 7 October.

At least 1.9 million people in Gaza – or about 90% of the population – have already been displaced, according to the UN.

The international body has indicated there is widespread malnutrition in Gaza, with experts backed by the organisation warning last month in a report that the "worst-case scenario" of famine is playing out in the Strip.

The war in Gaza was triggered by Hamas's 7 October 2023 attack on Israel, which killed about 1,200 people and saw 251 others taken hostage.

Israel's offensive has killed more than 61,000 Palestinians, according to figures from the Hamas-run Gaza health ministry, which the UN considers reliable.