Suspect 'acknowledged bombing role' The surviving suspect in the Boston Marathon attacks has told federal agents he and his late brother were motivated by extremist Islamic beliefs but that they were not connected to any known terrorist groups, say law enforcement officials. The officials said Dzhokhar Tsarnaev, 19, made the statements in an interview on Sunday from his hospital bed. They said Mr Tsarnaev acknowledged playing a role in the attacks, which killed three and injured more than 260, and that they believed the two men acted alone. His older brother, Tamerlan Tsarnaev, 26, was killed early Friday morning after a shootout with police. Crime scene: People walk past a barricade and makeshift memorial blocking a still closed section of Boylston Street near the site of the Boston Marathon bombings. Dzhokhar Tsarnaev's condition improved on Tuesday, officials said. He had been listed in a serious condition for several days by Beth Israel Deaconess Medical Centre, but was in a fair condition on Tuesday, the FBI said. On February 6 Tamerlan Tsarnaev bought fireworks at a Phantom Fireworks store in Seabrook, New Hampshire, about an hour's drive north of Boston, said William Weimer, the vice-president of Phantom Fireworks. He came in and he asked the question that 90 per cent of males ask when they walk into a fireworks store: What's the most powerful thing you've got? Mr Weimer said.