WATERTOWN, Mass. (AP) -
The two suspects in the Boston Marathon bombing killed an MIT police officer and hurled explosives at police in a car chase and gun battle overnight that left one of them dead and his brother on the loose, authorities said Friday as thousands of officers swarmed the streets in a manhunt that all but paralyzed the Boston area.
The suspects were identified by law enforcement officials and family members as Dzhokhar and Tamerlan Tsarnaev, brothers from a Russian region near Chechnya, which has been plagued by an Islamic insurgency that has carried out deadly bombings. They lived near Boston and had been in the U.S. for about a decade, an uncle said.
Tamerlan Tsarnaev, a 26-year-old who had been known to the FBI as Suspect No. 1 and was seen in surveillance footage in a black baseball cap, was killed overnight, officials said. His brother, a 19-year-old college student who was dubbed Suspect No. 2 and was seen wearing a white, backward baseball cap in the images from Monday's deadly bombing at the marathon finish line - escaped.
The law enforcement officials spoke on condition of anonymity because of the sensitivity of the unfolding case.
Authorities in Boston suspended all mass transit and warned close to 1 million people in the entire city and some of its suburbs to stay indoors as the hunt for Suspect No. 2 went on. Businesses were asked not to open. People waiting at bus and subway stops were told to go home.
The Middlesex district attorney said the two men are suspected of killing a Massachusetts Institute of Technology police officer on campus late Thursday, then stealing a car at gunpoint and later releasing its driver unharmed. Hours earlier, police had released photos of the marathon bombing suspects and asked for the public's help finding them.
Authorities say the suspects threw explosives from the car as police followed it into Watertown. The suspects and police exchanged gunfire, and one of the suspects was critically injured and later died while the other escaped.
"We believe this to be a terrorist," Boston police Commissioner Ed Davis said. "We believe this to be a man who came here to kill people."
The FBI said it is working with local authorities to determine what happened.
The MIT shooting on the Cambridge campus Thursday night was followed by reports of gunfire and explosions in Watertown, about 10 miles west of Boston.
The MIT officer had been responding to report of a disturbance Thursday night when he was shot multiple times, according to a statement from the Middlesex district attorney's office and Cambridge police. It said there were no other victims.
In Watertown, witnesses reported hearing multiple gunshots and explosions at about 1 a.m. Friday. Dozens of police officers and FBI agents were in the neighborhood and a helicopter circled overhead.
State police spokesman David Procopio said, "The incident in Watertown did involve what we believe to be explosive devices possibly, potentially, being used against the police officers."
Boston cab driver Imran Saif said he was standing on a street corner at a police barricade across from a diner when he heard an explosion.
"I heard a loud boom and then a rapid succession of pop, pop, pop," he said. "It sounded like automatic weapons. And then I heard the second explosion."
He said he could smell something burning and advanced to check it out but area residents at their windows yelled at him, "Hey, it's gunfire! Don't go that way!"
MIT said right after the 10:30 p.m. shooting that police were sweeping the campus in Cambridge and urged people to remain indoors. They urged people urged to stay away from the Stata Building, a mixed-use building with faculty offices, classrooms and a common area.
Hours later, MIT, which has about 11,000 students, said the campus was clear but the shooter was still on the loose.
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