by Alexandra Del Peral Agence France Presse LONDON, United Kingdom (AFP) — British police raced Saturday to track down whoever planted a bomb on a packed London Underground train, as authorities raised the national threat level to maximum, meaning another attack may be imminent. Friday morning’s blast, which left 29 people injured, was Britain’s fifth terror attack in six months and was claimed by the Islamic State group. Prime Minister Theresa May announced late […]