Dzhokhar Tsarnaev, 19, prime suspect in the Boston Marathon bombing is suffering gunshot wounds to the neck and leg and has lost a lot of blood, so it could be a while before investigators are able to talk to him.

CNN further reports that the young man might not be able to ever talk again.

Massachusetts Governor Deval Patrick said the suspect was stable, but not yet able to communicate, stressing authorities were hoping he will survive as they desperately needed answers.

Dzhokhar Tsarnaev, 19, was arrested late on Friday when he was found seriously injured in a suburban backyard after a huge manhunt.

He is under armed guard in hospital. CBS News quoted investigators as saying that the wound to the neck may have been a suicide attempt.

The teenager's brother, Tamerlan, died after a shoot-out with police.

Police officer Sean Collier was shot dead during the police operation to find the brothers on Thursday night. A transport officer was later seriously injured in the shoot-out which left Tamerlan Tsarnaev fatally wounded.

Three people were killed and more than 170 others injured by Monday's twin bombing, close the finish line of the Boston Marathon.

In a move criticized by rights activists, officials have said they intend to question the teenager without reading him his Miranda rights - the standard statement informing suspects they have a right to a lawyer and to remain silent - citing a "public safety exception."

Prosecutors are still determining what charges the teenager might eventually face.

A federal charge of using a weapon of mass destruction to kill people carries a possible death sentence. There is no death penalty in the state of Massachusetts.

Fox news informs the US authorities are investigating a lead of a possible connection between the brothers and the extremist group "Caucasus Emirate." Its leader, Doku Umarov, has claimed responsibility for a number of terror acts, including the explosion at the Domodedovo airport near Moscow in 2011.

One key line of inquiry will be a six-month trip made by Tamerlan Tsarnaev to Dagestan in the Russian Caucasus in 2012.

The FBI had interviewed Tamerlan in 2011 after a request from a foreign government, US law enforcements officials have confirmed, but agents closed the case after finding no cause for concern.

Several members of the Tsarnaev family have condemned and disowned the brothers, but their parents have said that they could not have planned such an attack as they were being monitored by the FBI.

Their mother, Zubeidat Tsarnaeva, said she was "100% sure that this is set up, insisting in an interview with Russia Today that her sons had never had any involvement with terrorism.