The Boston police stressed that there is no threat to public safety.
"Please be advised that there is not threat to public safety. Three additional suspects have been taken into custody in connection to the attack on the Boston Marathon," the Boston police department said in a statement uploaded on twitter.
Aside from the aforementioned, there is no additional info to release at this time, it said.
Authorities suspect the bombing was carried out by two Chechen-origin brothers, Tamerlan and Dzhokhar Tsarnaev.
Tamerlan was killed in a shootout with police days after the attack and Dzhokhar was injured and later taken into custody. Three people were killed and over 250 injured in the April 15 dual bombing near the finish line at the Boston marathon.
CBC News reported that federal charges are expected to be announced later today against the three suspects. It said that those arrested were "friends of younger brother Dzhokhar".
Two of the new suspects will be charged with conspiracy to obstruct justice and making false statements, it said.
The third will be charged with making false statements.
Sources told NBC News the three are college roommates or suitemates of Dzokhar and are suspected of removing items from his dorm at the University of Massachusetts-Dartmouth.
There was no indication they had any prior knowledge of the bombing.
Sources said the FBI had been investigating them for about 10 days.
News of the additional suspects comes after authorities said they had expanded their investigation and were reportedly interested in learning more about nearly a dozen persons of interest.