Three additional arrests have been made in connection with the
Investigators have been looking into whether other people conspired with
Following the announcement of the arrests, the Boston Police Department said in a tweet: "Please be advised there is no threat to the public."
Three people were killed and more than 260 injured when the bombs exploded near the marathon finish line.
Suspect Tamerlan Tsarnaev died after a gunfight with police several days later. His brother, Dzhokhar Tsarnaev, was captured and is hospitalized in a federal facility.
The arrests come after the