gaza children killed beach
Mourners carry the bodies of the four Palestinian children from the Bakr family, who were killed on a beach by a shell fired by an Israeli naval gunboatReuters

Eight members of the same family including four children, have been killed by tank fire in northern Gaza, it has been reported.

Two men, two women and the children were all members of the Abu Jurad family. They were killed in Beit Hanun as Israeli forces continue their ground offensive.

News of the latest civilian deaths comes as Israeli Prime Minister Benjamin Netanyahu warned of a "significant expansion" of the ground assault against the Gaza Strip.

The latest military offensive began on Thursday in a bid to infiltrate Hamas' underground network and to destroy the weapons arsenal, infrastructure and tunnels used by the militant group.

Hamas spokesman Sami Abu Zuhri called the ground offensive "foolish", adding that Israel would suffer "dreadful consequences" for their actions.

"Netanyahu is killing our children and will pay the price," he said. "The ground invasion doesn't frighten us and the occupation army will sink in Gaza's mud."

Earlier graphic photos were released of the bodies of four children, three from the Shuhaiber family, pictured at the morgue at Al Shiga Hospital in Gaza City, lying on a single mortuary slab.

The children were reportedly killed by an Israeli missile strike while they were feeding pigeons on the roof of their home in the Sabra neighbourhood of Gaza City.

The UN called for a humanitarian ceasefire after four more children were killed playing football on the beach.

In a brief truce following the child fatalities, Israel held fire to allow Gazans to stock up on food and other necessities.

The UN is now stepping up emergency aid to Gaza, where Israel's latest military offensive has worsened water shortages and increased fears of increased sewage contamination and water-borne diseases.

While the United Nations has condemned rocket fire into Israel from Gaza, it says it is "alarmed by Israel's heavy response."

UN Secretary General Ban Ki-moon is to travel to the region tomorrow to meet with Israelis and Palestinians.

More than 270 Palestinians have been killed since fighting began 11 days ago, with another 2,000 injured, according to the health ministry in Gaza.

Figures provided by the Gaza-based Palestinian Centre for Human Rights show that civilians account for more than 80% of the victims of Israel's assault since July 8.

A UN agency has said the number of displaced Gazans has almost doubled in the past 24 hours, hitting more than 45,000 people since the ground operation began.

Israel has confirmed two of its citizens have died.