Boston bombing suspect Dzhokhar Tsarnaev has pleaded not guilty to all charges against him.

He's appeared in court for the first time since April's attacks on the city's marathon, which killed three people and injured 260.

The 19-year-old wore handcuffs, shackles and an orange jumpsuit - and was watched by many of those who were hurt in the blasts.

Prosecutors say he wrote about his motivations in a boat where he hid before his capture - blaming the US government for killing Muslim civilians.

He's been remanded in custody.