BOSTON, MASSACHUSETTS — Police in Massachusetts are conducting a massive manhunt for one of the suspects in Monday's Boston Marathon bombings, after killing the other suspect in a shootout late Thursday. US media are reporting the suspects are brothers of Chechen origin.
Authorities say the "white hat" suspect from the marathon bombings, known as Suspect Two, is on the loose and is "armed and dangerous." Police are searching through the suburb of Watertown, about eight kilometers from Boston, and other parts of the Boston metropolitan area.
The suspects were driving a carjacked Mercedes SUV and police chased them after they were called to the scene of a robbery in Cambridge, across the river from Boston. Authorities say the suspects had fatally shot a campus police officer at the Massachusetts Institute of Technology.
Police say explosive devices were thrown at them from the fleeing car, and in an exchange of gunfire one of the suspects was shot, while the other fled in the vehicle.
Ed Davis, the commissioner of the Boston police department, said they believe the suspect is a terrorist.
"We believe this to be a man who has come here to kill people," he said. "We need to get him in custody.''
The first suspect was taken with multiple gunshot wounds to a hospital, where he was pronounced dead.
U.S. law enforcement officials say the two suspects in Monday's Boston Marathon bombing are legal U.S. residents of Chechen origin, identified as 19-year-old Dzhokhar Tsarnaev and 26-year-old Tamerlan Tsarnaev.
Officials say the elder brother died from wounds sustained during a shootout with police. Dzhokhar, the suspect wearing a white hat in video taken near the marathon bombings, has been called "Suspect Two" by police searching for him, and they say he is armed and dangerous.
The brothers were believed to be living in Cambridge, Massachusetts, and have at least one sister.
A young Chechen who lives in Boston and says he knew the family said the Tsarnaev family lived mainly in Central Asia before coming to the U.S. more than eight years ago.
Multiple sources, including Temirmagomed Davudov, a school headmaster in Makhachkala, the capital of the Russian republic of Dagestan, say the Tsarnaevs are originally from Kyrgyzstan and are of Chechen ethnicity. The headmaster said the two Tsarnaev brothers attended his school and left for the U.S. in 2002.
Friends of the two men say they were smart and athletic, the elder a boxer and the younger a wrestler.
Dzhokhar Tsarnaev graduated in 2011 from Cambridge Rindge and Latin School, about five kilometers from the center of Boston.
Police on Friday killed one suspect in the Boston Marathon bombing during a shootout and mounted a house-to-house search for the other suspect.
Authorities are urging residents throughout Boston and a number of its suburbs to stay indoors, as police lay a dragnet for the suspect.
Classes have been cancelled at schools and universities, and the entire public transport system of the Boston metropolitan area has been shut down.
Monday's bombings at the Boston Marathon killed three people and left more than 170 injured.