Where is the man in the white cap ?
The whole of the greater urban area of Boston has been put into a state of virtual lockdown as police continue a massive hunt for one of the suspects of the Boston Marathon bombing whom they have described as armed and extremely dangerous.
The Massachusetts governor, Deval Patrick, has ordered the immediate and indefinite shutdown of all public transport in Boston, and anyone already on the bus or subway services has been told to return to their homes. In Watertown, the western suburb of the city where two men believed to be the bombing suspects were chased in cars in the middle of the night, police have imposed a siege.
Residents of the town have been told not to go outdoors, and businesses in the town have been told not to open.
Ed Davis, the police commissioner of Boston, said officers were trying to apprehend a man identified in FBI photographs of the suspects on Thursday night as Suspect Two. The suspect was captured in video footage carrying a black rucksack and white baseball cap among the marathon crowd shortly before the bombings.
The other men, identified as Suspect One, was shot during the car chase, and later died. Suspect Two, however, remains at large.
During the car chase, explosives were thrown from the suspects' car, a black Mercedes SUV they car-jacked at the campus of MIT, where earlier in the night there was a shootout with police leading to the death of an MIT police officer.
Colonel Timothy Alben, head of Massachusetts state police, said: "This is a very serious situation. We believe these are the same individuals who were responsible for the bombings of the Boston Marathon and we believe they are responsible for the death of an MIT police officer and the shooting of another officer."
Kurt Schwartz, head of Massachusetts' emergency management division, said: "We are asking people to stay at home. We are asking people not to go outside or use mass transit."
Earlier, Ed Davis, the police commissioner of Boston, had the following advice for Watertown residents: "Do not open your doors. Stay in your home. We believe this man to be a terrorist and we need to get him into custody."
He said the death of the MIT police officer and the injury of another was "a terrible tragedy. We don't want to increase the tragedy."
In the photographs released by police, Suspect Two is seen wearing a grey hoodie and a basketball cap turned backwards. He has long, curly dark hair, and walked through the marathon crowd about five paces behind Suspect One.
Police have said Suspect Two was spotted placing a black bag outside the Forum restaurant, close to one of the bomb epicentres shortly before it detonated. That video has not been made public.
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