Four persons,who were picked up for questioning hours after an encounter in Noida,were later released after police ascertained their identities. "They had come from Jammu and Kashmir. Their identities were ascertained later. They were picked up on initial suspicion,but they had no connection with the terrorists killed in the encounter," a senior police official said on Monday. Two suspected Pakistani terrorists were gunned down by an Uttar Pradesh ATS team on Sunday while the ultras were trying to enter Delhi.