A late-night police chase and shootout has ended with one marathon bombing suspect being captured here, the Boston Globe reported. Meanwhile, an intense manhunt is underway for a second suspect in the terror case.
Federal agents swarmed neighboring Watertown after local police were involved in a car chase and shootout with at least two suspects. During the pursuit, officers could be heard on police radio traffic describing the suspects as having grenades and other explosives.
One reportedly escaped capture, and another was shot by police and taken to a local hospital. Another man was seen sprawled on the ground in footage shown on WHDH-TV.
The FBI has not confirmed a connection between the events in Watertown to the twin explosions that killed 3 people and injured 170 others at the Boston Marathon on Monday. But according to an alert sent issued to fellow officers, the suspect who remained at large was referred to as the "one with the white hat" seen in the photos released by the bureau on Thursday.
The suspect, described on scanner traffic as a "white male wearing a gray hooded sweatshirt with black curly hair, possibly with an assault rifle and explosives," as police in Watertown, Newton, Brighton and Cambridge were put on high alert.
"We are aware of the law enforcement activity in the greater Boston area," Boston FBI spokesman Greg Comcowich said in a statement to Yahoo News. "The situation is ongoing. We are working with local authorities to determine what happened."
[Related: FBI releases photos of suspects in Boston Marathon bombings]
Worried residents in Watertown, a suburb about 10 miles from downtown Boston, were ordered to stay indoors and turn off their cell phones out of fear that they could trigger improvised explosive devices.
Dozens of police officers, many of them off-duty, searched backyards in search of the second suspect, and a police perimeter of several blocks was established. K9 units and SWAT teams searched homes on Spruce Street as officers searched an SUV the suspects had abandoned.
The Watertown shootout occurred after a shooting at the Massachusetts Institute of Technology late Thursday. A police officer was shot and taken to a hospital where he was pronounced dead. The campus was placed on lockdown for several hours, and students were told to remain indoors.
Shortly before 2 a.m. Friday, MIT issued a statement on its website saying that the suspect "in this evening's shooting is no longer on campus. It is now safe to resume normal activities. Please remain vigilant in the coming hours."
At approximately 3:30 a.m., Massachusetts State Police issued a plea on Twitter for residents of Watertown to lock their doors and not open them for anyone.
"Residents in and around Watertown should stay in their residences," the alert read. "Do NOT answer door unless it is an identified police officer."