Plainclothes police chased a man in a thick coat through a subway station, wrestled him to the floor and shot him to death in front of stunned commuters Friday.
Appealing for help from the public to capture the suspects, police released photographs of four men suspected of launching Thursday's second wave of terrorist attacks, saying they bore similarities to the July 7 bombings that claimed 56 lives.
The driver of a double-decker bus in London says the windows of the bus were blown-out Thursday, one of a series of incidents that has brought much of the city to a standstill.
Police in chemical protection suits have been seen preparing to enter the Warren Street station.
