Three rockets have hit the southern Israeli town of Ashkelon, according to Sky sources - amid calls for a ceasefire as Israel's bombardment of Gaza continues.
The Israel Defence Forces said a school in the town had been hit. Police said 20 rockets were intercepted by Israel's Iron Dome anti-missile battery. Nobody was hurt.
Pictures from Gaza City in the early hours of Monday showed buildings in flames and thick, black plumes of smoke rising into the air.
Medics and Palestinian security officials said airstrikes across the Gaza Strip left at least 12 Palestinian civilians dead on Monday.
UN Secretary General Ban Ki-moon is on his way to the region to appeal for an end to the violence. He is expected to meet Egyptian President Mohamed Morsi before visiting Israel and Gaza.
Sky's Sam Kiley, in Gaza City, said there had been a "considerable lull" in attacks on both sides as Israel faces international pressure to head off a ground offensive and Hamas appears to show "goodwill" towards the idea of talks.
But he said shelling had been taking place some 600 metres from the scene of a funeral procession in Gaza, following the deaths of 11 people in an attack on the home of one family.
That airstrike happened on Sunday, the bloodiest day so far of Israel's Operation Pillar of Defence, with more than 120 targets hit and 29 Palestinians killed.
Gaza medics say women and children accounted for most of those killed, among them five babies and toddlers.
"This must stop," said Mr Ban. "I strongly urge the parties to co-operate with all efforts led by Egypt to reach an immediate ceasefire."
Israeli Prime Minister Benjamin Netanyahu has warned he is ready to expand the operation. The Reuters news agency quoted a senior Israeli official saying the country is ready for a ground invasion but prefers a diplomatic solution.
The mobilisation of 75,000 army reservists has already been authorised, suggesting a ground invasion could be imminent.
Talks to avert an escalation of violence will continue in Egypt later.
The Turkish Prime Minister and the Emir of Qatar are in the Egyptian capital, along with senior Israeli diplomats and representatives of Hamas.
British Foreign Secretary William Hague has warned Israel that it risks losing international sympathy if it escalates its campaign against Palestinian militants into a ground invasion.
Overall, the offensive that began last Wednesday has killed 94 Palestinians, including 50 civilians, and wounded some 720 people, Gaza heath official Ashraf al Kidra said. Among the wounded were 225 children, he said.
On the Israeli side, three civilians have died from Palestinian rocket fire and dozens have been wounded. Rocket-defence technology has intercepted rockets bound for populated areas.