LONDON—British police arrested three men under terrorism laws Sunday after a car exploded outside a hospital in Liverpool, killing one man and injuring another. Counter-terrorism police said the three men, whose ages ranged from 21 to 29, were detained in the Kensington area of the northwest England city under the Terrorism Act. Police also cordoned off another residential street in the city. They did not disclose details of the operation. Police were called to reports of a blast involving a taxi at Liverpool Women’s Hospital on Sunday morning. Photos showed a vehicle in flames near the hospital’s main entrance. Merseyside Police said in a statement that the vehicle, a taxi, “pulled up at the hospital shortly before the explosion occurred. Work is still going on to establish what has happened and could take some time before we are in a position to confirm anything.” The male passenger of the car …