Sources have told the Associated Press that that the Boston bomb suspects are from a Russian region near Chechnya and have lived in the US for at least one year.

One of the two suspects in the MIT officer shooting is dead but the other, who is tied to the Boston marathon bombing, remains at large, Boston police said.

A police officer has been shot dead and armed police have converged on a neighbourhood near Boston amid reports of explosive devices being used against them.

Sewage treatment plant workers discovered a baby’s arm, and US authorities said the remains could have come from any of 21 communities near Boston, Massachusetts.

A woman whose skeleton was found in a chimney was a murder victim, investigators said, but her name and manner of death remain a mystery.