The manhunt for the second suspect involved in the Boston Marathon bombing attack is fully under way.

The two suspects, as identified by law enforcement, are two brothers from Chechnya, Dzhokhar,19, and Tamerlan Tsarnaev, 26. The elder Tsarnaev was labeled as Suspect No. 1 by the FBI and was seen in surveillance footage wearing a black outfit and carrying a black duffel bag. The younger brother can be seen wearing a white baseball hat.

After robbing a 7-11 convenience store Thursday night, authorities were alerted to their position and followed suit.

But, before the authorities caught up with the suspects to apprehend them, they shot and killed MIT police officer, Sean Collier, 26, who was on duty, according to The Associated Press.

They then hijacked a car and held the victim at gunpoint until releasing him/her. The pursuit didn't end there as the two brothers began hurling explosive devices at the pursuing officers, injuring one transit officer, according to AP.

The two suspects were identified in surveillance footage from the convenience store near Cambridge and the MIT campus. The police knew who they were dealing with based upon a testament from the victim of the car jacking.

In the midst of the pursuit and exchange of bullets, law enforcement managed to kill the elder Tsarnaev, reports AP. However, the younger brother managed to flee.

"We believe this man to be a terrorist," said Boston Police Commissioner Ed Davis. "We believe this to be a man who's come here to kill people."

The manhunt for the Suspect No. 2 is currently underway as Boston has shut down mass transit and warned 1 million people in the suburbs to stay indoors as SWAT teams, snipers, FBI and police comb the area between Watertown and Cambridge.

Read more here about the two suspects.