At least eight more poor miners were kidnapped from Marwar, the suburban area of the city, sources said.
Marwar has turned into blood flashpoint, where bodies of seven miners who were abducted from here on July 7, were found yesterday.
The bereaved families and co-workers of the victims yesterday approached Balochistan High Court (BHC) and mounted protest against the killings.
The traffic was held up with pickets erected on Zarghoun Road during the demonstration. On attempting to enter the high court premises, they were baton-charged.
The demonstrators demanded action against the miscreants responsible for kidnapping and killings.
The four of the deceased belonged to Dir and Swat areas of Khyber Pakhtunkhwa.
Taking notice of the incident, Chief Justice of Pakistan (CJP) Iftikhar Muhammed Chaudhry demanded a detailed report from the provincial home secretary.