Three arrests made in Boston bombing investigation

Three men who attended college with the Boston Marathon suspect have been charged in connection with the case. Boston Police say there was no threat to public safety.

Azamat Tazhayakov and Dias Kadyrbayev are charged with conspiring to obstruct justice. A third man, Robel Phillipos, is charged with making false statements to federal investigators.

Authorities say the three men didn't want Dzhokhar Tsarnaev to get in trouble for the bombings.

An FBI affidavit says the three men removed bombing suspect Dzhokhar Tsarnaev's backpack from his dorm room at the University of Massachusetts at Dartmouth three days after the bombing.

Authorities say the three students concluded from news reports three days after the bombings that Dzhokhar Tsarnaev was one of the bombers. According to court papers, they went to Tsarnaev's dorm room and found a backpack with fireworks that had been emptied of powder.

The FBI says the three removed the backpack and a laptop from the room, and went to an apartment to watch news reports featuring photographs of Tsarnaev.

According to the affidavit, one of the men told authorities that the three then decided together to "throw the backpack and fireworks into the trash because they did not want Tsarnaev to get into trouble."

Tazhayakov and Kadyrbayev, both from Kzakhstan, have been held in jail for more than a week on allegations that they violated their student visas while attending UMass Dartmouth with Dzhokhar Tsarnaev. They have

been held in a county jail

for more than a week.

The three men aren't accused of any direct involvement in the bombing. But according to court papers, the FBI said that about a month before the bombing, Tsarnaev told two of them that he knew how to make a bomb.

Boston attorney Linda Cristello represented them and confirmed they now face separate federal charges and have a court appearance Thursday afternoon related to the Boston Marathon bombing.

The FBI had reportedly been investigating them for 10 days, according to NBC News, although the suspects were likely not involved in the bombings.

In a tweet Wednesday morning

, the police department says only that three more suspects are in custody and more details will follow. Police spokeswoman Cheryl Fiandaca confirmed the tweet but referred all other questions to the FBI.

Three people were killed and more than 260 injured on April 15 when two bombs exploded near the finish line.

Suspect Tamerlan Tsarnaev died after a gunfight with police several days later. His brother, Dzhokhar Tsarnaev, was captured and lies in a hospital prison.

Both are Russian natives who lived for several years in the U.S. They are accused of using a weapon of mass destruction.

(Information from the Associated Press was used in this report.)