MOSCOW, August 14 (RAPSI, Ingrid Burke) - Dias Kadyrbayev and Azamat Tazhayakov, college friends of Boston Marathon bombing suspect Dzhokhar Tsarnaev, pleaded not guilty Tuesday to obstruction of justice charges connected with the investigation into the tragic explosions that left three dead and upwards of 200 injured near the finish line of the enormously popular marathon in April, RIA Novosti reported.

The two were indicted Thursday by a US federal Grand Jury for their alleged efforts to impede the investigation.

Kadyrbayev and Tazhayakov are listed in a statement by the US Attorney’s Office for the District of Massachusetts as 19-year-old nationals of Kazakhstan, residing in the US on student visas.

At about 2:49pm on April 15, two explosions occurred near the finish line of the Boston Marathon. IEDs devised from pressure cookers, low explosive powder, shrapnel, adhesive, and other materials were hidden in backpacks that were then placed near metal barricades in areas packed with hundreds of spectators, according to Tsarnaev’s indictment.

According to the Kadyrbayev / Tazhayakov indictment, “Each explosion killed at least one person, maimed, burned and wounded scores of others, and damaged public and private property, including the streets, sidewalk, barriers, and property owned by people and businesses in the locations where the explosions occurred.”

The following four days were consumed by a dramatic and at times extremely violent manhunt for the suspects, who were identified by name on April 19 as Dzhokhar (19) and his brother Tamerlan Tsarnaev (26). The manhunt entailed the presence of thousands of law enforcement personnel from local, state, and federal agencies, and resulted in a veritable lockdown through parts of the greater Boston area.

Tamerlan was killed during a police shootout, and Dzhokhar was arrested on the evening of April 19 after having been discovered hiding in a dry-docked boat in the Boston suburb of Watertown.

According to their indictment, Kadyrbayev and Tazhayakov entered the US on student visas sometime around September 2011. Dzhokhar Tsarnaev, Kadyrbayev, Tazhayakov, and an unnamed alleged co-conspirator all began studying at the University of Massachusetts at Dartmouth at the same time in 2011 and became friends, who “spent time together socializing, and often exchanged text messages with each other.”

The FBI searched the dorm room Dzhokhar had been living prior to the bombing on April 21. However, the Kadyrbayev / Tazhayakov indictment alleges that by that point, the room had already been picked through. According to the indictment, on the evening April 18, after the FBI had publicly posted images of the as-yet unidentified Tsarnaev brothers, Kadyrbayev, Tazhayakov, and the unnamed alleged co-conspirator removed a number of items from Dzhokhar’s dorm room, including the bombing suspect’s laptop computer and a backpack containing fireworks.

The backpack was then allegedly discarded in a dumpster outside of the apartment Kadyrbayev and Tazhayakov shared, and was later discovered by federal agents in a local landfill.

When it was found, the backpack allegedly contained fireworks, a jar of Vaseline, a thumb drive, and a homework assignment sheet.

Notably, Tsarnaev’s indictment claimed that at some point prior to the bombing, Dzhokhar had downloaded the first volume of Inspire magazine, described as an “English language online publication of al-Qaeda in the Arabian Peninsula.” The volume allegedly contained detailed instructions on the construction of IEDs using pressure cookers and explosive powder from fireworks, among other components.

The Kadyrbayev / Tazhayakov indictment asserts that Kadyrbayev received a text message from Dzhokhar that he showed to Tazhayakov on the evening of April 18 that stated: “If yu [sic] want yu [sic] can go to my room and take what’s there [smiley face] but ight [sic] bro [sic] Salam aleikum.”

While searching the dorm room, Kadyrbayev allegedly discovered the backpack containing fireworks, the containers of which “had been opened and manipulated. As a result, some of the explosive powder was visible.” Kadyrbayev then allegedly expressed his belief to Tazhayakov that a jar of Vaseline present in the room had been used by Dzhokhar “to make bombs.”

After returning to their own apartment, Kadyrbayev, Tazhayakov, and the unnamed alleged co-conspirator allegedly discussed the fate of the evidence. After deciding to toss the backpack and fireworks in the garbage, Kadyrbayev and Tazhayakov allegedly watched the news as the story publicly unfolded, and then watched as garbage men collected the contents of the dumpster.

Kadyrbayev and Tazhayakov have been charged with conspiracy to obstruct justice and with the obstruction of justice with intent to impede, obstruct, and influence the Boston Marathon bombing investigation. Their arraignment is scheduled for Tuesday August 13 at 2pm.

According to a press release issued by the US Attorney’s Office for the District of Massachusetts, Kadyrbayev and Tazhayakov face up to 20 years in prison if convicted on the obstruction of justice count, and five years in prison for conspiracy. Both face the possibility of deportation, as well.