Israel has closed the Kerem Shalom crossing with Gaza after Hamas fired rockets from within the strip, the military has said.
At least 10 people were injured, some seriously, Israeli media report.
The crossing is one of the few routes to get humanitarian aid into Gaza.
The attack came as mediators in Egypt held talks to broker a ceasefire – and to release Israeli hostages. Israel has said it will not accept Hamas’s demands to end the Gaza war.
The Israeli Defense Forces (IDF) said 10 projectiles were fired from an area near the Rafah crossing in southern Gaza, located approximately 3.6km (2.2 miles) from Kerem Shalom.
According to the IDF, they were fired from a site some 350m from a civilian shelter and were “another clear example of the systematic exploitation that the Hamas terror organisation makes of humanitarian facilities and spaces for terror needs, while using the civilian population as a human shield”.
Israeli fighter jets then struck the launcher from where they were fired and another military structure close by, it said in a statement.
The war began after waves of Hamas gunmen stormed across Gaza’s border into Israel on 7 October, killing about 1,200 people and taking more than 250 hostages. The group is proscribed as a terrorist organisation by many Western countries.
During the subsequent Israeli military campaign in Gaza, more than 34,600 Palestinians have been killed and over 77,900 wounded, according to figures from the territory’s Hamas-run health ministry.
Hamas sent a delegation to the truce talks in Cairo said to involve a 40-day pause in fighting while hostages were released, and the release of a number of Palestinian prisoners being held in Israeli jails.
The main sticking point appeared to be whether the truce would be permanent – as Hamas insists – or not.
On Sunday, Israeli Prime Minister Benjamin Netanyahu said the proposed ceasefire deal would keep Hamas in control of Gaza, posing a threat to Israel.
“The state of Israel cannot accept this [Hamas’s demands], we are not prepared to accept a situation in which the Hamas brigades come out of their bunkers, take control of Gaza again, rebuild their military infrastructure, and return to threatening the citizens of Israel in the settlements surrounding the southern mountains, in all parts of the country.
“This will be a terrible defeat for the state of Israel,” he added.
Mr Netanyahu has faced pressure from within his far-right coalition to press ahead with the long-promised offensive in Gaza’s southern-most city, Rafah, where an estimated 1.4 million people have taken shelter after fleeing fighting in northern and central parts of the strip.
The US – Israel’s biggest diplomatic and military ally – is reluctant to back a new offensive that could cause significant civilian casualties, and has insisted on seeing a plan to protect displaced Palestinians first.
The Israeli government also faces mounting pressure at home.
Of the 252 hostages who were kidnapped by Hamas on 7 October, 128 are still unaccounted for – and among them, at least 34 are presumed dead.
Ceasefire talks have gone on for months without a breakthrough, and there has not been a pause in fighting or a release of hostages since the end of November.
There have been moments at which a new agreement has seemed imminent – only to fall through before being signed.
