Men arrested over the Boston Marathon bombing are accused of destroying a rucksack belonging to one of the suspects.
College friends of suspect Dzhokhar Tsarnaev stand accused of removing the backpack, which contained fireworks that had been emptied of gunpowder, from his room after the attack, according to the AP news wire.
Boston Police has confirmed that three "additional suspects" are in custody, and stressed there was no danger to the public.
Police say Azamat Tazhayakov and Dias Kadyrbayev, who are both from Kazakhstan, threw away Dzhokhar Tsarnaev's laptop and his backpack.
They are reported to be friends of Dzhokhar Tsarnaev, a friend from the University of Massachusetts Dartmouth where they were all students at one time.
American Robel Phillipos has been charged with making false statements to law enforcement officials.
The US Attorney's Office said the three men faced "conspiring to obstruct justice and false statements charges".
Dzhokhar Tsarnaev was captured by police after the bombing, which killed three people. His brother, Dzhokhar Tsarnaev, was killed in a gunfight with police.
On Wednesday night it was reported that Kadyrbayev and Tazhayakov face a maximum sentence of five years in prison and a $250,000 fine, while Phillipos could face the same fine and up to eight years in jail.