France arrests four over Lyon blast

French police have arrested a 24-year-old Algerian computer student suspected of planting a bomb in Lyon last week that wounded 13 people, authorities said on Monday.Three other people were also arrested in connection with the case, which is being treated as a terrorism investigation.A man was spotted by security cameras leaving the explosive device, with screws and metal balls packed into a paper bag, in a pedestrian shopping street in the central French city on Friday a minute before it explod