"Dzhozkar, if you’re alive, turn yourself in and ask for forgiveness from the victims, the injured and those who are left," Ruslan Tsarni said on Friday. "He put a shame on our family. He put a shame on the entire Chechen ethnicity. Turn yourself in."

Tsarnaev, 19, was still at large on Friday, despite a massive manhunt that has put Boston and its western suburbs into lockdown. He and his brother, Tamerlan Tsarnaev, are suspected of planting two shrapnel-filled bombs near the finish line of the Boston Marathon that killed three and injured at least 170.

After the FBI released photos and videos of the two suspects on Thursday evening, the Tsarnaev brothers allegedly launched a spree of violence that continued through the night. Tamerlan Tsarnaev was killed in a violent confrontation with police after he and his brother allegedly shot and killed an MIT police officer and carjacked a Mercedes Benz SUV.

Ruslan Tsarni, a resident of Montgomery Village, Md., spoke to reporters outside his home. Tsarni said he had not spoken to his nephews in several years and called them "losers" unable to "settle themselves in."

Tsarni said his nephews had no political motives and were not connected to any radical activity in Chechnya, even though the family are ethnic Chechen.

"They've never been to Chechnya!" Tsarni said.