The Israeli army has launched artillery towards Lebanon - on its northern border - in response to rocket fire from there.

"Six failed launch attempts were identified from Lebanon that did not cross into Israeli territory," the army said in a statement.

"Artillery forces fired toward the sources of the launches."

A Lebanese security source said shells were heard being fired from south Lebanon and efforts were being made to identify the location. The source said about 22 shells were fired by Israeli artillery on Lebanese territory.

There were no reports of casualties or damage, and the shelling did not appear to signal the opening of a new front in Israel's fighting with militants in the Gaza Strip.

It was the second incident of cross-border fire in the past week. On Thursday, three rockets were launched from Lebanon toward northern Israel but landed in the Mediterranean Sea, causing no damage or casualties.

Earlier, US President Joe Biden announced he would talk with Israeli Prime Minister Benjamin Netanyahu, shortly after diplomats said Washington had blocked a third draft of a UN Security Council resolution calling for an end to the violence.

Meanwhile Israeli jets kept up a barrage of airstrikes against the Palestinian enclave of Gaza this evening, as a week of violence that has killed more than 200 people shows no signs of relenting.

Air strikes sent dust clouds billowing into the skyline, as the Hamas militant group that controls the densely populated coastal strip threatened more rocket strikes on Tel Aviv if bombing of residential areas did not stop.

After a Palestinian journalist told how he escaped with his family from an attack which killed 15 of his neighbours, Gaza resident Roba Abu al-Awf, 20, said she was bracing for a rough night.

"We have nothing to do but sit at home," she said. "Death could come at any moment - the bombing is crazy and indiscriminate."

Palestinian militants have fired 3,200 rockets toward Israel since the conflict escalated on 10 May in the heaviest exchange of fire in years, sparked by unrest in Israeli-annexed east Jerusalem.

The Qatari Red Crescent said an air strike damaged its offices in Gaza today, while the health ministry said one of its buildings and a clinic were also hit.

A young woman and her dog run for shelter in Ashdod, Israel as sirens warn of rocket fire from Gaza

Israel's army said it had hit the homes of nine "high-ranking" Hamas commanders overnight, a day after bombing the house of Yahya Sinwar, head of the group's political wing.

It gave no details of any casualties.

Fighter jets also hit what the Israeli army calls the "Metro," its term for Hamas' underground tunnels, which Israel has previously acknowledged run in part through civilian areas.

The strikes come a day after 42 Palestinians in Gaza - including at least eight children and two doctors, according to the health ministry - were killed in the worst daily death toll in the enclave since the bombardments began.

Local authorities said a total of 200 Palestinians have been killed in Gaza, including at least 59 children, and more than 1,300 wounded since Israel launched its air campaign against Hamas in response to rocket fire.

Israel said 10 people, including one child, have been killed and more than 300 wounded by the rocket fire that has been the most intense to ever rain down on the Jewish state.

Israeli bombardment of Gaza has displaced 38,000 people and made 2,500 homeless, the United Nations has said.

It has also battered crucial infrastructure, with the electricity authority today warning it only had enough fuel left to provide power for another two to three days.

Gaza's only Covid-19 laboratory is no longer able to carry out testing due to an Israeli air strike, local authorities said.

Al-Rimal clinic, in the town of the same name in the Gaza Strip, was partly destroyed.

Ministry spokesman Ashraf Qidra said the Israeli strikes "threaten to undermine the efforts of the health ministry in the face of the Covid pandemic".

The raids "stopped screening tests... at the central laboratory", he added.