Families of 11 children accused of terrorism staged a sit-in outside Governor House in Quetta and blocked Saryab Road for traffic on Monday.
Police had arrested around a dozen children, some as young as 10, suspected of being used to plant bombs for separatist militants.
The CPO said a Baloch militant organisation had lured the children, who came from menial backgrounds, to leave packages containing home-made bombs in markets, dustbins and on routes used by police and security forces. The children had confessed to their crimes.
However, families of the nabbed youths staged a sit-in demanding that the children be released.