One of the air strikes killed 11 people from a single family, health officials said.
Mussa Dhaheer, looking on from below as neighbours helped an emergency worker lower a victim in a black body bag from an upper storey, said he had awakened to the blast, kissed his terrified daughter and rushed outside to find the destruction.
His father, 75, and mother, 62, were among the dead.
"I don't know what to do. I don't know what to say. I can't make sense of what happened. My parents. My father with his displaced friends who came from Gaza City," he told Reuters.
"They were all together, when suddenly they were all gone like dust."
The Israeli army says it is targeting Hamas militants who use civilian buildings for cover. (AP PHOTO)
At another bomb site, Jamil Abu Houri said the intensification of air strikes was Israel's way of showing its disdain for a United Nations Security Council resolution last week demanding an immediate Israel-Hamas ceasefire.
Next up, he fears a ground assault on Rafah, which Israel has threatened for weeks to carry out despite pleas from its closest ally the United States that this would wreak a humanitarian disaster.
"The bombing has increased, and they have threatened us with an incursion, and they say that have been given the green light for the Rafah incursion. Where is the Security Council?" Abu Houri said.
"Look at our little ones. Look at our children. Where should we go? Where should we go?"
Another Israeli air strike in Rafah on Wednesday afternoon killed four Palestinians including a woman and a child and injured other residents, Gaza health authorities said.
Just west of Gaza City in the enclave's north, seven people were killed in an air strike on a house, health officials said.
The Israeli military says it is targeting armed Hamas militants who use civilian buildings, including apartment blocks and hospitals, for cover.
Hamas denies doing so.
Separately, in the Israeli-occupied West Bank, three Palestinians were killed and four wounded by Israeli fire during a raid in Jenin overnight, the Palestinian health ministry said.
At least 32,000 Palestinians have been killed in Israel's air and ground offensive into Hamas-run Gaza, according to the health ministry there, with thousands of other dead believed buried under rubble and more than 80 per cent of the 2.3 million population displaced, many at risk of famine.
The war erupted after Islamist Hamas militants broke through the border on October 7 and rampaged through nearby communities, killing 1200 people and abducting 253 hostages according to Israeli tallies.
Israeli forces just north of Rafah kept the two main hospitals in Khan Younis, al-Amal and Nasser Hospital, under a blockade imposed late last week.
In the north, they were still operating inside al-Shifa, the enclave's largest hospital, which they stormed more than a week ago.
Israel says the hospitals have been lairs for Hamas gunmen, which Hamas and medical staff deny.
The Israeli military has said it killed and captured hundreds of fighters in a battle in al-Shifa.
Hamas says civilians and medics were rounded up.
Residents living nearby have reported hearing explosions in and around al-Shifa and columns of smoke coming from buildings inside the premises.
International mediation has failed to secure a ceasefire and exchange of prisoners so far as the two sides stick to irreconcilable demands.
Hamas wants an end to the war and total Israeli withdrawal from Gaza while Israel has vowed to keep fighting until its Islamist foe is eradicated.
