Two college friends of Boston bomber accused Dzhokhar Tsarnaev pleaded not guilty on Tuesday to removing evidence from his university dormitory room.
Dias Kadyrbayev and Azamat Tazhayakov, both 19, appeared in a federal court in Boston. They are accused of taking a backpack containing fireworks and a laptop computer from his room to stop the FBI finding them.
Both are from Kazakhstan and could face 25 years in prison.
The bag was dropped in a dumpster outside the New Bedford, Massachusetts, apartment where the pair lived. The FBI later found it in a landfill.
Neither is charged with involvement in the bombing.
The two have been in federal custody since 1 May.
Dzhokhar Tsarnaev, 20, is accused of setting off two bombs at the finish line of the Boston Marathon on 15 April, killing three people and wounding 264.
He is also charged in the death of a university police officer from whom he and his older brother, Tamerlan Tsarnaev, are accused of trying to steal a gun.
