Israeli planes have carried out 13 air strikes on the Hamas-ruled Gaza Strip, Palestinian sources have told the BBC.

Four of the strikes took place near the town of Khan Younis, where two Israeli soldiers were killed in clashes with Palestinian fighters last week.

The Israeli military has told the BBC the operation was targeting four weapons factories.

The strikes are the most serious for more than a year, says the BBC's Jon Donnison from Jerusalem.

The director of ambulance and emergency in the Palestinian Ministry of Health, Dr Muawiya Hassanein, said that three children
BBC News - Thirteen Israeli air strikes hit Gaza Strip