BOSTON (Reuters/AFP) - A United States grand jury has indicted accused Boston Marathon bomber Dzohkhar Tsarnaev on 30 charges of
killing four people and using a weapon of mass destruction, federal prosecutors in Boston said on Thursday.

Tsarnaev, 19, is one of two ethnic Chechen brothers accused of carrying out the April 15 attack. He faces the death penalty or life imprisonment on 17 of the counts.

Three people were killed and more than 260 were wounded in the bombings at the finish line of the Boston marathon.

A fourth victim, a university police officer, died in a gunfight with the pair four days later as the authorities raced to capture them.

The younger Tsarnaev, who was badly injured in that gun battle, has been held in a prison hospital west of Boston since his capture on April 19.