Washington, May 16 (EFE).-

The surviving suspect in the April 13 Boston Marathon bombings, Dzhokhar Tsarnaev, wrote a note claiming responsibility and citing U.S. action in Iraq and Afghanistan as the reason for the attack, CBS News reported Thursday.

Dzhokhar, 19, scrawled the message on the walls of the boat where he holed up after the gunbattle with police that resulted in the death of his brother and fellow suspect, 27-year-old Tamerlan Tsarnaev, sources told John Miller of CBS.

The younger Tsarnaev, who was wounded in the shootout, may have written the note because he expected to die in the boat.

He is continuing to recover at a prison hospital in Massachusetts.

Dzhokhar characterized the Boston attack as a reprisal for U.S. military action in Afghanistan and Iraq, describing the three people killed and more than 200 wounded in the blasts as "collateral damage."

"When you attack one Muslim, you attack all Muslims," he wrote on the wall of the boat.

He also addressed Tamerlan's death, saying that he did not mourn his brother because the older man was a martyr in paradise.

Miller said the note will serve as evidence in Dzhokhar's trial.