Katy Conrad, CBS news producer, broke the news of the charges:
Update 11:30 a.m.: Boston.com reports that the three were "connected" to Dzhokhar Tsarnaev at college:
Update 11:55 a.m.: Williams reports more specifics:
Sources told NBC News the three are college students who are suspected of removing items from the dorm room of Dzokhar Tsarnaev, 19, who is charged with placing a bomb at the finish line of the April 15 race.
It was unclear if the persons in custody had any knowledge or involvement in the bombing or its aftermath.
The Globe reports that Azamat Tazhayakov and Dias Kadyrbayev are among the three charged.
Tazhayakov and Kadyrbayev are both Kazakh UMass Dartmouth students who were friendly with Tsarnaev. They were held in county jail on student visa violations for the last week, and their lawyers say they were extensively interviewed.
Update 2:10 p.m.: The third suspect is Robel Phillipos. Here's the affadavit:
Police say there is no threat to the public.
[image of Tazhayakov and Kadyrbayev with Tsarnaev via Kadyrbaev's home page]