"Yes, we're ashamed. They're the children of my brother," Ruslan Tsarni told a throng of reporters outside his home in Montgomery Village, Md.
The suspects were identified by law enforcement officials and family members as Dzhokhar and Tamerlan Tsarnaev, brothers from a Russian region near Chechnya.
Tamerlan Tsarnaev, a 26-year-old who had been known to the FBI as Suspect No. 1 and was seen in surveillance footage in a black baseball cap, was killed overnight, officials said.
His brother, a 19-year-old college student who was dubbed Suspect No. 2, escaped.
He was seen wearing a white, backward baseball cap in the images from Monday's deadly bombing at the marathon finish line.
"Dzhokhar, if you are alive, turn yourself in and ask for forgiveness," Tsarni said.
Tsarni called his nephews "losers" and said his family had not seen them since December 2005. They lived near Boston and had been in the U.S. for about a decade.
Tsarni said his brother left the U.S. and he had not talked to him since 2009.
Chechnya has been plagued by an Islamic insurgency that has carried out deadly bombings.
Tsarni said vehemently that Chechnya had nothing to do with the attack. He said his nephews had struggled to settle themselves in the U.S. and ended up "thereby just hating everyone."
