Hamas fires rockets at southern Israeli city of Ashkelon

Hamas has fired rockets on the southern Israeli city of Ashkelon after warning people to leave by 17:00 local time (15:00 BST). Air raid sirens have been sounded across Israel throughout the day - the military says more than 4,500 rockets have been fired since Saturday. Israel said it's killed two top Hamas officials while continuing to bomb the Gaza Strip; the group itself has not confirmed this. A BBC reporter in Gaza said it was the worst bombing he had seen in 20 years, with neighbourhoods flattened.