Israeli strikes in Gaza killed at least eight people, including a child, according to hospitals cited by the BBC. The ceasefire began a year ago.
Earlier on Sunday, Al Jazeera English reported that Israeli attacks on Gaza City and Khan Younis had killed at least nine people.
In Gaza City, hospital officials said a missile hit a group of civilians next to Cairo School in the Al-Rimal neighbourhood. They said three people died, including a four-year-old boy.
Speaking outside Shifa Hospital after the Gaza City strike, Ali Oweis said: "My son and his child were martyred. They were sitting in their tent, bothering no one, and nothing else was happening in the area when suddenly, a missile struck them, and they were martyred". The BBC quoted him from AFP.
He also told AFP: "There is no ceasefire; the war is ongoing, don't you see?"
In Khan Younis, the Hamas-run interior ministry said a drone attack hit a group of police officers in the Al-Mawasi area. It said five of them were killed while on routine duty. The ministry named the five dead officers, who were aged between 23 and 53, and called the attack a massacre.
The Israeli military said it carried out two attacks on what it described as military operatives. It has not yet provided evidence or further information.
A ceasefire took effect in Gaza in October of last year. Israeli air strikes have continued almost daily since then. A Gaza peace plan brokered by the Trump administration has stalled.
According to Gaza's Hamas-run health ministry, 1,580 people have been killed since the ceasefire began. The UN considers the ministry's figures reliable. The ministry says 74,594 people have been killed in Gaza since the war began.
The war was triggered by the Hamas-led attack on Israel on 7 October 2023. About 1,200 people were killed and 251 were taken hostage. The ceasefire brought the release of thousands of Palestinians held by Israel in exchange for the 48 remaining hostages.