Manchester terror attack: Police arrests man at Heathrow Airport in connection to concert blast

People attend a vigil for the victims of attack at a pop concert at Manchester Arena, in central Manchester. Reuters[/caption]Police said the 38-year-old man was arrested on Tuesday night. He has not been identified or charged.Officials say the arrest had been planned and that there was no direct threat to the busy airport.Salman Abedi killed 22 people at the Ariana Grande concert by detonating a bomb. Police says Abedi built the bomb largely on his own but may have the support of a network. Few details of the investigation have been released and no one has yet been charged.Seven men remain in custody on suspicion of violating the Terrorism Act. Police have released 12 other people without charges.