Israel on Saturday carried out its heaviest airstrikes in Gaza in weeks, killing at least 32 people, Palestinian health officials said.

Violence has persisted in the Palestinian territory despite a US-brokered ceasefire entering its second phase earlier this month. Both Israel and the Palestinian militant group Hamas have accused each other of violating the fragile truce agreement.

A series of strikes hit locations across Gaza on Saturday, including a Hamas-run police station, apartments in Gaza City and a tent camp in Khan Younis, according to local officials.

"The death toll since dawn today has risen to 32, most of them children and women," said the civil defence agency, a rescue force operating under the Hamas authority. This update increased an earlier toll of 28.

"Residential apartments, tents, shelters and a police station were targeted, resulting in this humanitarian catastrophe," agency spokesman Mahmud Bassal said. 

What else do we know about the series of Israeli air strikes?

Health authorities in the Hamas-run enclave say at least 509 Palestinians have been killed by Israeli fire in Gaza since the ceasefire came into effect, while Israel's military says four soldiers have been killed in suspected militant attacks.

While deaths have been reported almost daily in Gaza since the ceasefire began on October 10, Saturday's number was several times higher than the daily average.

The Israeli military said in a statement that the strikes were in response to what it called a breach of the ceasefire on Friday. The IDF said eight Palestinians were detected exiting a tunnel in the southern Gaza city of Rafah, adding that at least three of them were killed.

It said forces "struck four commanders and additional terrorists from the Hamas and Islamic Jihad terrorist organisations across the Gaza Strip."

Strikes come ahead of plans to reopen Rafah crossing

Hamas called Saturday's strikes "a brutal crime." The group is designated as a terrorist organization in Israel, the US and several other countries.

The attacks were carried out a day before the Rafah border crossing between the Gaza Strip and Egypt is due to ‌reopen for the "limited movement of people" after nearly two years of closure.

Both Egypt and Qatar, co-mediators of the ceasefire, condemned the Israeli strikes.

Egypt demanded that all parties "exercise the utmost restraint" ahead of Sunday's reopening of Rafah crossing, while Qatar said it denounced the "repeated Israeli violations of the ceasefire."

Edited by: Dmytro Hubenko