NEW YORK (AFP) - A new book will explore the life of the Tsarnaev brothers, the ethnic Chechens accused of bombing the Boston marathon, a New York publishing house announced on Wednesday.

The book - so far untitled and without a publication date - will be written by Russian-American journalist Masha Gessen, who covered the Chechnya war in the 1990s and is an expert on the Chechen diaspora, Riverhead Books said in a statement.

"The book will explain who the brothers were, where they came from, what shaped them, and how they came to do what they appear to have done," the statement said.

"From their displaced beginnings, as descendants of ethnic Chechens deported to Central Asia in the Stalin era, it will follow the brothers from strife-ridden Kyrgyzstan to war-torn Dagestan, and then, as new emigres, to the looking-glass, utterly disorienting peace and order of Cambridge, Massachusetts."

Tamerlan Tsarnaev, 26, who was killed in a shootout with police, and Dzhokhar, 19, are accused of the April 15 attack that killed three people and wounded more than 260.

The younger brother was arrested on April 19 and is currently being held at a prison hospital 60km from Boston.