European countries ramped up pressure on Israel to abandon its intensified campaign in Gaza and let more aid into the war-ravaged territory, where rescuers said fresh attacks killed dozens of people on Tuesday.

An AFP journalist saw some trucks entering the Kerem Shalom crossing into Gaza from the Israeli side on Tuesday, a day after the UN said it had been cleared to send aid for the first time since Israel imposed a total blockade on March 2, sparking severe shortages of food and medicine.

The dire humanitarian situation in the Strip has prompted an international outcry, with the European Union saying it would review its trade cooperation deal with Israel over alleged human rights abuses following a foreign ministers' meeting on Tuesday.

The bloc's top diplomat Kaja Kallas said "a strong majority" of its 27 member states backed the move, adding "the countries see that the situation in Gaza is untenable... and what we want is to unblock the humanitarian aid".

Sweden said it would press the EU to level sanctions against Israeli ministers.

"Since we do not see a clear improvement for the civilians in Gaza, we need to raise the tone further," said Foreign Minister Maria Malmer Stenergard.

And Britain suspended free-trade negotiations with Israel, summoned the Israeli ambassador and said it was imposing sanctions on settlers in the occupied West Bank in its toughest actions so far against Israel's conduct of the war.

"Blocking aid, expanding the war, dismissing the concerns of your friends and partners. This is indefensible and it must stop," Foreign Secretary David Lammy said in an impassioned speech to parliament.

Responding to Britain's moves, Israeli foreign ministry spokesman Oren Marmorstein said "external pressure will not divert Israel from its path in defending its existence and security".

COGAT, the Israeli defence ministry body that oversees civil affairs in the Palestinian territories, said "93 UN trucks carrying humanitarian aid, including flour for bakeries, food for babies, medical equipment, and pharmaceutical drugs were transferred" to Gaza on Tuesday.

The spokesman for UN chief Antonio Guterres confirmed dozens of trucks were allowed in, but spoke of difficulties receiving the deliveries.

"Today, one of our teams waited several hours for the Israeli green light to... collect the nutrition supplies. Unfortunately, they were not able to bring those supplies into our warehouse," Stephane Dujarric said.

UN humanitarian chief Tom Fletcher said that the nine trucks cleared to enter on Monday were "a drop in the ocean of what is urgently needed".
He told the BBC on Tuesday that 14,000 babies could die in the next 48 hours if aid did not reach them in time.

US Secretary of State Marco Rubio, replying to a Democrat's comment during a Senate Foreign Relations Committee meeting, said he understood "that it's not in sufficient amounts, but we were pleased to see that decision was made" to restart aid shipments.

Israeli strikes overnight and early Tuesday left "44 dead, mostly children and women, as well as dozens of wounded", civil defence spokesman Mahmud Bassal told AFP.

Bassal said 15 people were killed when a petrol station was hit near the Nuseirat refugee camp, and eight others were killed in a strike on a school sheltering displaced Palestinians in Gaza City to the north.

At the bombarded petrol station, Nuseirat resident Mahmoud al-Louh carried a cloth bag of body parts to a vehicle.

"They are civilians, children who were sleeping. What was their fault?" he told AFP.

In a statement on Tuesday, the military said it had carried out strikes on more than "100 terror targets" in Gaza over the past day.