police officers
police officers AFP file

Police have arrested three more suspects as part of the investigation into the Boston marathon bomb attack that left three dead and more than 260 wounded.

"Three additional suspects taken into custody in Marathon bombing case. Details to follow," the Boston Police Department said on Twitter, according to AFP.

"Please be advised there is no threat to the public," the message added.

One of two ethnic Chechens, 19-year-old Dzhokhar Tsarnaev, is currently in custody and has been charged with carrying out the bombing.

His brother, 26-year-old Tamerlan Tsarnaev, was killed on April 18 during the manhunt for the pair.

The brothers are suspected to have detonated backpacks holding pressure cookers packed with explosives near the finish line of the April 15 race. They are also accused of killing a police officer during their time on the run.

Police did not immediately offer more details of the arrests, but the Boston Globe newspaper reported that the suspects were college students who are alleged to have helped Dzhokhar following the attack.

NBC News reported the new suspects are accused of helping their fellow student gather his belongings from his campus accommodation and may have attempted to mislead authorities.