Israeli tank shelling and airstrikes killed 21 Palestinians, including six children, in Gaza on Wednesday, health officials said, the latest violence to undermine a truce in the enclave.

Among the dead was a medic who rushed to help victims of a strike in the southern city of Khan Younis and was then killed by a second attack on the same location, health officials said.

Other strikes hit Gaza City in the north, where health officials said a 5-month-old boy was killed. The attacks come three days after Israel reopened Gaza's main border crossing with Egypt, a major step in the US-backed truce.

“While we were sleeping in our house, the tank shelled us and the shells hit our house, our children were martyred - my son was martyred, my brother’s son and daughter were martyred... We have nothing to do with anything, we are peaceful people,” said Abu Mohamed Habouch, speaking at a funeral for his family.

Tents in Mawasi, a coastal area near Khan Younis crowded with Gazans displaced by the conflict, had been ripped apart by the strikes. Nearly all of Gaza’s over 2 million population has been forced to flee their homes.

The Israeli military said it had launched the strikes in response to militants opening fire against Israeli troops operating near its armistice line with Hamas.

It said an Israeli soldier was severely injured by the militant fire, which it described as a violation of the ceasefire agreement.

Hamas said Israel’s action undermined efforts to stabilise the ceasefire. In a statement, the group called for “immediate international pressure to halt violations.”

Rafah reopening

Palestinian patients preparing to cross through the newly opened Rafah border crossing to Egypt were told that Israel had postponed the passage of patients through the border. A few hours later the patients were told to prepare again to cross the border.

The Israeli agency that controls access to Gaza, COGAT, said in a statement that Rafah crossing remained open, but it had not received the necessary coordination details from the World Health Organization to facilitate the crossing.

The WHO did not immediately respond to a Reuters request for comment.

An Egyptian security source told Reuters that efforts were being made to reopen the crossing, and that Israel had cited security issues in the Rafah area as the reason for the closure.

Reopening the crossing was one of the requirements under the October ceasefire that set out the first phase of US President Donald Trump’s plan to stop fighting between Israel and Palestinian Hamas militants.

Sixteen patients from Gaza and 40 of their escorts crossed into Egypt on Tuesday, Gazan medics told Reuters. A Hamas police source told Reuters that at least 40 people crossed from Egypt to Gaza late on Tuesday.

Wednesday’s violence brings the number of Palestinians killed since the border reopened to 29, according to a tally of reports from Gazan health officials.

On Saturday, before its reopening, Israeli strikes killed more than 30 Palestinians in Gaza. The military said it launched those strikes after gunmen emerged from a tunnel in a Gaza area under Israeli control.

Second phase of ceasefire

In January, Trump declared the start of the second phase of the ceasefire where the sides would negotiate the shattered enclave’s future governance and reconstruction.

Key issues like the withdrawal of Israeli forces from the over 50% of Gaza they currently occupy and the disarmament of Hamas remain unresolved, while the fragile ceasefire has been marked by near-daily violence.

Since the start of the ceasefire, Israeli fire has killed at least 530 people, most of them civilians, according to Gaza health officials. Palestinian militants have killed four Israeli soldiers in the same period, according to Israeli authorities.

Israel’s two-year offensive on the Gaza Strip killed more than 71,000 Palestinians, according to Gazan health authorities, displaced most of its population, and left much of the strip in ruins.

The October 7, 2023, Hamas attack that triggered the war killed around 1,200 people in Israel, according to Israeli tallies.