The Boston marathon bomber Dzhokhar Tsarnaev spoke for the first time in court yesterday, since being found guilty of killing three people and injuring more than 260 others at the race in 2013.

He had been hearing victim impact statements, before being formally sentenced to death.

Speaking in court he said: "I ask Allah to have mercy on me my brother and my family."

"I am sorry for the lives that I've taken, for the suffering that I've caused you, for the damage that I've done. Irreparable damage," he said.

Tsarnaev (21) struggled to maintain his composure as he spoke for five minutes shortly before he was formally condemned to die by lethal injection.

Survivors were divided on whether his apology was genuine.

The mother of a woman who died in the attack told Tsarnaev what he did was 'disgusting'.

Lynn Julien said his remarks "were sort of shocking" and disputed whether he had shown true remorse.

"A sincere apology would've been nice," she told reporters.

Another survivor, Henry Borgard, welcomed Tsarnaev's statement and said he hopes he finds peace.

Fox25 reporter Bob Ward told Newstalk Breakfast an appeal of the sentence is likely.