Dzhokhar Tsarnaev, the surviving suspect in last week’s Boston Marathon bombing, has claimed that his elder brother Tamerlan was the driving force behind the attack, according to a report.

Dzhokhar has reportedly said that Tamerlan - who died in hospital last Friday - wanted to defend Islam from attack.

Preliminary interviews with Tsarnaev indicate the two brothers fit the classification of self-radicalized jihadists, a government source has revealed, according to CNN.

The government source cautioned that the interviews were preliminary, and that Tsarnaev’s account needs to be checked out and followed up on by investigators.

Federal prosecutors charged Tsarnaev in hospital with using a weapon of mass destruction and malicious destruction of property resulting in death.

The surviving suspect could be sentenced to death if convicted on either count.