One Boston marathon bombing suspect has been shot dead, while another, believed to be "armed and dangerous", is being chased by police and the Federal Bureau of Investigation.
"We do not have an apprehension of our suspect this afternoon. But we will," Massachusetts state police chief Timothy Alben told reporters after 6:00 p.m. local time, adding it was believed that the suspect, 19-year-old Dzhokhar Tsarnaev, is still in the northeastern US state.
"For the sake of everyone that was hurt or killed during the marathon, or those police officers that lost their life, or were seriously injured, we are committed to seeing a conclusion to this case," he added, according to AFP.
Governor Deval Patrick said an earlier order for residents to stay at home had been lifted, and announced the reopening of Boston's "T" subway system.
"We are asking the public to remain vigilant," Patrick said. "But we feel confident based on what we know about the status of the investigation right now that, to that extent, we can return to living our lives."
The suspect's brother, a man identified by several sources as Tamerlan Tsarnaev, 26, died after an overnight shootout with police. He was the man described by the FBI as black-capped Suspect No. 1 in the attacks Monday that killed three.
The 19-year-old brother, however, escaped, leading police to throw a huge dragnet around the region.
In photos released by the FBI on Thursday of the bombing suspects, the younger brother is seen wearing a white cap. The agency called him Suspect No. 2.
One police officer was also shot dead and a second wounded during the late night operation in Watertown, near Boston, authorities said.
Police forces sealed off much of the town as they killed one suspect and continue to hunt for the other, according to reports.
State Police announced in the early hours of the morning that they would be going “door to door, street by street, in and around Watertown.” They warned residents to stay inside and not answer the door unless the person is clearly identified as a law-enforcement officer, The Boston Globe reported.
On Friday afternoon, U.S. authorities said they would carry out a "controlled explosion" before a search of a house that may have been used by the two suspects.
State police colonel Timothy Alben told reporters, according to AFP, that the precautionary explosion would be carried out for the safety of law enforcement officials "before they proceed with a search" of a house.
The origin of the terrorists is Chechnyan. Commentator Victor Sharpe, who has written extensively on the threats to the world from resurgent Islam, told Arutz Sheva:
"We must remember that on September 1st, 2004, Chechen terrorists took some 1,000 Russians captive at a school in Beslan, southern Russia, and held them for three days. During that time the Chechens slaughtered 186 children and 148 adults. Among the Chechen terrorists were women.
"Chechnya is predominantly Muslim. Most of the Chechens belong to the Shafi'i school of thought of Sunni Islam, while a minority belong to the Hanafi.
"It has been an aim of Islamic terrorists and jihadists to use people who do not look Arab or Middle Eastern to commit atrocities on soft targets in the U.S in order for them to blend in better with the majority population. This could be the first wave of such terror. It is particularly ghastly that in view of the horrendous injuries suffered by the victims at the Boston Marathon the younger brother who helped perpetrate the atrocity was studying medicine in the Boston area."
The curfew follows reports that a gunman shot and killed a Massachusetts Institute of Technology police officer on Thursday in an eruption of gunfire at the prestigious university.
The university said the situation was "extremely dangerous" and warned students in an emergency alert on its website to stay indoors, adding that one building on campus had been surrounded by police.
Massachusetts State Police spokesman David Procopio said early Friday that the violent events at MIT and Watertown appeared to be connected, and that federal authorities were investigating whether the violence of Thursday night and Friday was connected to the marathon bombings, earlier in the week, according to The Globe.
Authorities made no comment on whether there was a link between the manhunt and Monday's bombing in which three people were killed and about 180 injured.
However the operation came only hours after the Federal Bureau of Investigation released photos of the suspects they believe planted the bombs.
A second police officer was wounded in a gunfight in the town, they added.
(Arutz Sheva’s North American Desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)