An Israeli missile slammed into a tent encampment in the southern Gaza Strip on Tuesday just as displaced people had gathered there to watch a football match at a school, eyewitnesses said on Wednesday.

At least 29 people, mostly women and children, were killed in the strike, according to Palestinian officials, which took place as spectators crowded the school grounds in Abassan east of Khan Younis and hawkers sold smoothies and biscuits.

"They were watching a football match. There were injuries and martyrs. I witnessed this ... people thrown around and body parts scattered, blood," a young woman, Ghazzal Nasser, said in Abassan.