The Human Rights Commission of Pakistan (HRCP) has expressed concern over missing Hindus in Sindh, saying it has received several complaints of "enforced disappearances".
It has demanded that the law enforcement authorities and intelligence agencies must either release the citizens or disclose the charges against such illegally arrested and kidnapped people.
They should also disclose the law under which they have been arrested, the place of detention, and the name of the court where any case against them may be pending, HRCP's Zohra Yusuf said in Karachi.
She said the authorities must allow friends and relatives of the detainees to meet them regularly, saying this was a basic human right guaranteed under law.
A majority of Pakistan's Hindus, estimated at a little over 1 percent of the 145 million, reside in Sindh province.
Pinpointing specific cases, she said that on Sep 9, 55-year-old Gordhan Das (alias GM Bhagat) of district Umerkot was picked up reportedly by four law enforcement personnel in plainclothes.
Bhagat was carried off in a double-cabin government vehicle from a spot close to his residence, GM Baghat House, opposite the session court.
Bhagat's son Om Prakash filed a case in the Hyderabad High Court, the HRCP said.
In the same district, Chetan Kumar was arrested as an alleged "terror suspect" in 2001 and sentenced by the Special Anti-Terrorism Court in Hyderabad.
He was reportedly tortured and abused in custody. The Sindh High Court acquitted him.
In July 2006, eight armed law enforcement agents abducted him again from his house.
Kumar and his son were tortured, and Chetan Kumar's whereabouts are still unknown, HRCP said.