TIMELINE: Manhunt for Boston Marathon bombing suspects

Key developments in the massive manhunt for the Boston Marathon bombing suspects are listed below:

5:20 p.m. Thursday: The FBI releases images and videos of two suspects that investigators believe carried out Monday’s bombing near the finish line at the Boston Marathon.

10:20 p.m. Thursday: Shots are fired on the MIT campus in Cambridge.

10:30 p.m. Thursday: An MIT campus police officer who was responding to a disturbance is found in his vehicle suffering from multiple gunshot wounds, in a reported confrontation with the Boston Marathon bombing suspects. He is pronounced dead in hospital.

— Shortly afterward, two armed men reportedly carjack a Mercedes SUV in Cambridge. The man in the vehicle is held for approximately half an hour and released unharmed at a Cambridge gas station.

— Police pursue the carjacked vehicle in Watertown, a suburb west of Cambridge.

— Authorities say some sort of explosive devices are thrown from the vehicle. The suspects and police exchange gunfire, in which a transit police officer is seriously injured. One suspect — later identified as Suspect No. 1 in the Boston Marathon bombings — is critically injured and later pronounced dead.

— A massive manhunt gets underway for the suspect at large.

Approximately 1 a.m. Friday: Gunshots and explosions are heard in Watertown. Police officers and FBI agents zero in on a Watertown neighbourhood. A helicopter circles overhead.

Approximately 4:30 a.m. Friday: At a brief news conference, Massachusetts state and Boston police tell residents in that area of eastern Watertown to remain in their homes. They confirm that the suspects in an armed carjacking are the same men suspected in the Boston Marathon bombings.

Police also release a new image of a man believed to be Suspect No. 2, apparently taken from store surveillance video earlier in the evening at a 7-Eleven convenience store in Cambridge. He is wearing a grey hoodie-style sweatshirt.

Approximately 5:50 a.m. Friday: Authorities tell residents in Watertown, Newton, Waltham, Belmont, Cambridge, Arlington and the Allston-Brighton neighbourhoods of Boston to stay indoors. All mass transit is shut down.

Approximately 6:35 a.m. Friday: The Associated Press reports that the marathon bombing suspects are from a Russian region near Chechnya and lived in the United States for at least a year.

Approximately 6:45 a.m. Friday: The Associated Press identifies the surviving Boston bomb suspect as Dzhokhar A. Tsarnaev, 19, who has been living in Cambridge.

Approximately 8 a.m. Friday: Boston’s police commissioner says all of Boston must remain in their homes as the hunt for the suspect at large is underway.

Approximately 8:40 a.m. Friday: A U.S. law enforcement official and the uncle of the suspects confirm that the name of the deceased suspect is Tamerlan Tsarnaev, who is Dzhokhar Tsarnaev’s older brother.

Approximately 10:20 a.m. Friday:  A grey Honda CRV believed to be linked to Dzhokhar Tsarnaev is recovered in Boston, according to Connecticut State Police.

Approximately 10:35 a.m. Friday: The University of Massachusetts Dartmouth says it closed its campus and ordered an evacuation after confirming that Dzhokhar Tsarnaev is registered there. The school says it closed the campus “out of an abundance of caution.”

Approximately 11:30 a.m. Friday: Massachusetts State Police explain that the brothers suspected in the bombings were in the Honda CRV when they carjacked the Mercedes SUV. For a while, each drove one of the two vehicles, but then ditched the Honda and reunited in the Mercedes.

Approximately 12:35 p.m. Friday: State police in Watertown say officers are searching door-to-door but still have not found the bombing suspect.

— Maret Tsarnaeva, the Toronto aunt of the Boston Marathon bombings suspects, says she does not believe her nephews were behind the attacks.

Approximately 3:20 p.m. Friday: The NHL and MLB postpone games in Boston.

Approximately 6:10 p.m. Friday: Boston police say the suspect at large has not been apprehended. The stay-indoors order is lifted but Gov. Deval Patrick urges residents to remain vigilant.

6:55 p.m. Friday: Police cruisers seen rushing to a scene in Watertown. Numerous gunshots heard.

7:15 p.m. Friday: CNN say police have cornered second suspect inside a boat in a resident’s backyard at 67 Franklin St.

8:15 p.m. Friday: Police remain at the scene. Some reports tear gas has been fired. Other reports state the boat is on fire.

8:45 p.m. Friday. Boston police tweet they have the second suspect in custody after a brief but tense standoff.