At least 23 people have been killed in tribal clashes in Egypt's southernAswan province, officials said on Saturday.Long-standing tensions between Bani Hilal tribesmen and the Nubian Dabudiyafamily erupted after a woman was accosted on Thursday, the interior ministry said.Tribal vendettas are common in Egypt's poor, rural south, but police called theoutbreak of violence the worst in recent memory.The health ministry said 20 people were killed in renewed fighting on Saturday a dayafter a failed reconciliation meeting between the two sides ended in a gun battlethat killed three.Security officials said earlier the meeting took place on Thursday.Police said the clashes had subsided by Saturday afternoon after they sent inreinforcements to quell the unrest.Police began to reassert themselves across the country only recently, after abreakdown in law and order following a 2011 uprising that overthrew strongmanHosni Mubarak.