Four people have been killed and a further 70 injured after Israeli tank shells hit a hospital in central Gaza, according to Palestinian medics.
Thirty of those wounded in the attack were reportedly medical staff.
Health official Ashraf al Kidra said 12 shells hit the intensive care unit, surgery department and administration building at the al Aqsa hospital in the town of Deir el-Balah.
A Palestinian man salvages a mattress from the remains of his house
Footage on Hamas' al Aqsa TV station showed chaotic scenes at the facility.
In an earlier Israeli airstrike, 28 members of the same family were killed near Gaza's southern border with Egypt, according to medics.
Meanwhile, the Israeli army claimed it killed more than 10 Hamas militants who entered Israel via cross-border tunnels.
Palestinian men mourn the death of their relatives at a morgue in Rafah
Grainy video released by the Israeli Defence Forces (IDF) showed what appeared to be Hamas gunmen in a firefight with Israeli forces before they were hit by an airstrike.
The film showed several armed men lying in the grass near what Israel claimed was the exit to the tunnel on the Israeli side.
After exchanging fire the men appear to retreat before they are hit by what Israel claimed was an airstrike.
Officials say some 35,000 Palestinians have been fleeing the bombardment
There was no way of verifying the video.
One of the tunnels came out just one kilometre (half a mile) from the southern Israeli town of Sderot, the IDF said.
Military radio claimed the "second terrorist squad" tried to approach Niram kibbutz, close to Gaza's northeastern tip, where they engaged in gunfire with Israeli soldiers.
Several soldiers were hurt, the radio report said, without giving further details.
The family of Major Tsafrir Bar-Or during his funeral in Holon, Israel
Hamas' armed wing the Ezzedine al-Qassam Brigades claimed it had carried out "an operation behind enemy lines in response to the massacre in Shejaiya [Shaja'iya]".
The attack came as the UN Security Council urged an "immediate cessation of hostilities" in a call echoed by US President Barack Obama in a telephone conversation with Israeli Prime Minister Benjamin Netanyahu.
US Secretary of State John Kerry has flown to Cairo to try to broker a end to the two-week-long conflict after previous ceasefire talks were unsuccessful.
Israeli soldiers mourn during the funeral of colleague Bnaya Rubel in Holon
Israel's continued aerial bombardment has resulted in an exodus of some 35,000 civilians, according to officials.
People fleeing Israeli shelling in Shaja'iya at the weekend described it as a "massacre", with many women and children among the dead.
The Israeli army said it had given civilians two days warning to leave the area.
Meanwhile, Israel's UN ambassador Ron Prosor denied claims by Hamas that an Israeli soldier had been abducted.
Pro-Israel supporters rallied at Times Square, New York at the weekend
Palestinian President Mahmoud Abbas described the situation in Gaza as "intolerable" and the Israeli attacks a "crime against humanity".
The Israeli government has claimed Hamas is hiding behind the civilian population.
Spokesman Naftali Bennet said: "What Hamas is doing is effectively self genocide.
"They're, in a cowardly and cynical fashion, placing their women and children as shields, killing them, then coming to Sky News and other outlets and saying 'Israel is killing us'."