Gunmen have killed Moussa Arafat, a top advisor to the Palestinian Authority. A cousin of the late president, Yasser Arafat, he was an aide to the current leader Mahmoud Abbas on military affairs and a former national security chief.He was assassinated in Gaza city. It is reported his son was kidnapped. Nobody has claimed responsibility. Moussa Arafat survived an attempt on his life two years ago. He was deeply unpopular with radical Palestinians for cracking down on armed groups. They also saw him as a symbol of what they denounced as endemic corruption within the Palestinian Authority.