The attacks on Saturday also wounded 87 others, according to authorities in Gaza.
Witnesses said the first strike hit a car in northern Gaza City, and was followed by more attacks in central Deir el-Balah and the Nuseirat refugee camp.
The drone attack in Gaza City killed at least 11 people and wounded 20 others, according to the managing director of al-Shifa Hospital, Rami Mhanna. It happened in the city’s Remal neighbourhood.
In Deir el-Balah, at least three people, including a woman, were killed when an Israeli strike hit a house there.
The Israeli attack on Nuseirat also hit a residential building.
According to the Gaza Government Media Office, Israel has violated the United States-brokered ceasefire at least 497 times since it came into effect on October 10.
Some 342 civilians have been killed in the attacks, with children, women and the elderly accounting for the majority of the victims.
“We condemn in the strongest terms the continued serious and systematic violations of the ceasefire agreement by the Israeli occupation authorities,” the office said in a statement.
“These violations constitute a flagrant breach of international humanitarian law and the humanitarian protocol attached to the agreement. Among these violations, 27 occurred today, Saturday, resulting in 24 martyrs and 87 wounded,” it added.
