A 19-year-old man who authorities said gave himself up to police shortly after carrying out a deadly shooting in a Southern California synagogue filled with Sabbath worshippers is also under investigation in connection with an unsolved mosque arson.

A gunman opened fire on Jewish worshippers at a synagogue in the US city of Pittsburgh yesterday, leaving 11 people dead according to US media, in what appeared to be one of the worst anti-Semitic attacks in American history.