The HRW had sent a letter to Thai Prime Minister Prayut Chan-ocha, warning that the Pakistani Christian and Muslim Ahmadi minorities were threatened by discriminatory laws and attacks by religious extremists in their country, reports Efe news.
"It's critically important for Thai authorities to free Pakistanis recognized as refugees from detention and not to return any into harm's way in violation of international law," said Brad Adams, Asia Director of HRW, said in a statement.
Dozens of Pakistanis have been detained by Thai authorities in police raids targeting more than 1,000 immigrants, mostly from South Asia, for not possessing valid visas, the statement said.
The non-profit asked Thailand to respect the UN Convention against Torture of which it is a signatory and allow the UN High Commissioner for Refugees access to the detainees.
Thailand treats asylum seekers and refugees as immigrants, having failed to sign the 1951 Refugee Convention and the UN Protocol Relating to the Status of Refugees of 1967.
The Pakistani Ahmadis, a Muslim sect founded by Mirza Ghulam Ahmad in India in the 19th century, are victims of religious persecution and are not allowed to identify themselves as Muslims in Pakistan.
Christians, too, are victims of discrimination and repression in the country.
Last week, a Christian woman, Asia Bibi, was acquitted by the Pakistani Supreme Court, in a case of blasphemy that had created a global outcry.
The top court had annulled the death penalty given to her in 2010 after she was charged under the country's notorious blasphemy laws for insulting Prophet Muhammad.
Muslims comprise around 95 per cent of Pakistan's population, while the rest five percent are mostly made up of Christians, Hindus and Ahmadis.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)