Boston police on Wednesday announced the arrests of three new suspects in connection with the April 15 bombings that killed three people and wounded some 280.

Until now, Chechen brothers Dzhokhar and Tamerlan Tsarnaev had been the only suspects in the double-bomb attack at the finish line of the Boston Marathon.

Tamerlan, 26, died in a shootout with police a few days after the attack, while 19-year-old Dzhokhar remains in the hospital wing of a prison.

The three men are Azamat Tazhayakov and Dias Kadyrbayev, both 19-year-old Kazakhs, who allegedly helped Dzhokhar to dispose of a computer and a backpack, and U.S. citizen Robel Phillipos, also 19, who stands accused of lying to authorities.

The three were students at the University of Massachusetts Dartmouth with Dzhokhar, although none of them is facing charges for having participated in planning the bomb attack or knowing of it beforehand.

According to the indictment presented Wednesday in a Massachusetts court, the men are alleged to have removed and destroyed evidence from Dzhokhar's room on the university campus that could have implicated him in the attack.

The two Kazakhs were arrested on April 20 for alleged immigration visa violations.

Authorities say that the three students went to Dzhokhar's room after the FBI released the video showing images of the presumed bombers and they suspected that their friend could have been involved, and they later went to a dump near the town of New Bedford to get rid of the items they found.

Kadyrbayev said during questioning by law enforcement that he had destroyed Dzhokhar's belongings "to help his friend."

According to a source in the Department of Homeland Security quoted by CNN, authorities will file charges related to the obstruction of justice against the three young men.

The FBI found the DNA of a woman on fragments of at least one of the bombs used in the attacks, but it has not yet determined whose DNA that is or if she might be implicated in the preparation of the devices.

FBI agents spoke this week with Katherine Russell, Tamerlan's widow, who has been cooperating with authorities.

President Barack Obama on Tuesday defended the "exemplary" work of the police with regard to the Boston attack after criticism that they could have done more to prevent the bombings was leveled at the city's law enforcement personnel.

The FBI's activities in the matter also have been thrown into question for having closed an investigation on Tamerlan the agency began in 2011 at Russia's request. EFE