Boston Marathon Bombing Update: Two friends of suspect Dzhokhar Tsarnaev to be arraigned on obstruction charges

(CBS/AP) BOSTON - Two college friends of Dzhokhar Tsarnaev, the surviving Boston Marathon bombing suspect, face arraignment on charges of disposing evidence from the suspect's dorm room.

PICTURES: Boston bombing victims

PICTURES: Boston Marathon bombing suspects

Dias Kadyrbayev and Azamat Tazhayakov are scheduled to be arraigned Tuesday afternoon in federal court on charges of conspiracy to obstruct justice.

If convicted, they face up to 20 years in prison.

Prosecutors say the 19-year-old men, both from Kazakhstan, tried to interfere with the investigation into the April 15 explosions by throwing away fireworks and other items they found in Tsarnaev's dorm room the day before his capture.

Authorities later discovered the fireworks in a New Bedford landfill.

Like Tsarnaev, they were students at the University of Massachusetts Dartmouth at the time.

Lawyers for both men have said they did nothing wrong.

The April 15 attack at the Boston Marathon killed three people and wounded more than 260. Authorities say Tsarnaev orchestrated the attack along with his older brother, Tamerlan Tsarnaev, who died following a shootout with police three days after the bombing.

Dzhokhar Tsarnaev, 19, was arrested on April 19 when he was found hiding in a boat in a suburban Boston backyard. He was initially charged in the hospital, where he was recovering from wounds suffered in a police shootout. He faces 30 charges, including using a weapon of mass destruction to kill, and has pleaded not guilty.

Martin Richard, 8; Krystle Marie Campbell, 29; and Lingzi Lu, 23 - were killed by the bombs, which were improvised from pressure cookers. Authorities say the Tsarnaevs also killed Massachusetts Institute of Technology police officer Sean Collier days later while they were on the run.

Complete coverage of the Boston Marathon bombings on Crimesider