More chaos in Boston. Unsure if they related to the bombings or not:
A GUNMAN has been surrounded by authorities after fleeing a fatal police shooting at a major Boston university. LIVE UPDATES BELOW.
Here's what we know so far.
A policeman was shot and killed at the Massachusetts Institute of Technology, a university within walking distance of this week's Boston marathon bombings
Suspects armed with grenades and firearms are understood to have then commandeered an SUV
A wild police chase followed from the university to the nearby suburb of Watertown
Gunfire and a series of explosions were heard by residents
It is believed suspects were carrying firearms and homemade explosives
State police said suspects were throwing grenades out of the stolen vehicle.
It is understood there are at least two suspects
One suspect was stripped naked and taken into custody and has now been released
Another was on the ground surrounded by police
Soldiers from the National Guard, the FBI, state and local police are on the scene.