The number of people who have been displaced by Israel's ongoing offensive on the Gaza Strip has soared to over 58,000, the UN said on Tuesday.

The new figure represents an increase of 20,000 since the international body gave its last assessment of 38,000 displaced Gazans on Monday.

UN spokesman Stephane Dujarric said 47,000 people have sought protection in 58 UN-run schools across the coastal enclave amid ongoing Israeli attacks that continued to target civilian infrastructure overnight Monday.

That included Gaza's central COVID-19 testing lab "and other health and humanitarian facilities," Dujarric told reporters.

"There will be a great need for reconstruction of the infrastructure that was destroyed in Gaza. The Palestinian people will need the help of the international community, the financial help of the international community. We will get involved in it as much as we can," he said.

The total number of people killed in ongoing Israeli attacks on the besieged Gaza Strip has risen to 213 on Tuesday, including 61 children, 36 women, and 16 elderly people, according to the Gaza-based Palestinian Health Ministry.

As many as 1,400 people have also been injured in the attacks.

Ten Israelis have also been killed in Palestinian rocket fire from the Gaza Strip into Israel.

Israel has allowed dozens of United Nations Relief and Works Agency for Palestine Refugees (UNRWA) fuel trucks into Gaza, but continues to block delivery of "other essential humanitarian cargo," Dujarric said.

"As far as the security situation allows, the UN along with our partners provide food and non-food items to displaced families, and immediate cash assistance to more than 56,000 people," he said.