At least 18 Palestinians, including children, have been killed in renewed clashes and Israeli attacks in the Gaza Strip, Palestinian media reported on Saturday, underscoring the fragility of the ceasefire that took effect last month.

Five people were killed in an Israeli strike on a vehicle in Gaza City, the WAFA news agency reported, saying the attack occurred in the city's Rimal neighbourhood.

Videos circulating on social media showed a charred car with what appeared to be bodies nearby.

An Israeli army spokesman said the incident was under investigation.

Saudi broadcaster Al-Hadath reported that a commander of Hamas' military wing, the al-Qassam Brigades, was killed in the strike, along with his son. Hamas has not confirmed the report.

WAFA later reported that one person was killed when a house was shelled in Nuseirat, located in central Gaza.

Four people were killed in another attack on Deir al-Balah, including two children, the agency said.

Israel reports attacks on Hamas fighters

The Israeli military said it had carried out several strikes on Hamas targets in Gaza in response to an armed attack on Israeli soldiers in the south of the Strip.

One militant had crossed the ceasefire line, misusing a route used for humanitarian aid deliveries to the Gaza Strip, the military said on Telegram. The man fired at soldiers and was subsequently "eliminated."

Another five militants were killed in the southern city of Rafah who had apparently emerged from an underground tunnel, according to the military.

In two further incidents in the north of the coastal strip, four fighters were identified who had crossed the ceasefire line and approached troops, "posing an immediate threat to them," the military said, adding that two of the men were killed.

Violence has flared sporadically since a ceasefire between Israel and Hamas came into effect on October 10. Gaza's Hamas-controlled health authority says more than 300 Palestinians have been killed since then.

Since the Gaza war erupted, it says nearly 70,000 people have died in the coastal territory.

The conflict began after Hamas launched a large-scale attack on southern Israel on October 7, 2023, which killed around 1,200 people and saw more than 250 taken to Gaza as hostages.

Hamas in recent days has been accusing the Israeli military of shifting the "yellow line" in Gaza further west. Under the ceasefire agreement, Israeli forces withdrew beyond this line, although they continue to control more than half of the territory.

An Israeli military official said the line had not been moved and is marked with large yellow concrete blocks.