Police let the 18- and 19-year-old men go Sunday night and appealed to anyone with information about whoever killed Lyra McKee to come forward.
McKee was fatally wounded during rioting Thursday night in the city of Londonderry.
Police say she was probably hit by a bullet someone fired at police. Video from the scene showed a gunman wearing a black face mask aiming at officers.
The two teens were arrested under an anti-terrorism law on Saturday. Their release means authorities are still seeking the person who pulled the trigger.
McKee's funeral is scheduled to be held in her native Belfast on Wednesday.
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