'The investigation needs to be prompt, fair and carried out by an independent body,' Amnesty International said.

'All findings of the investigation must be made public and all those responsible for the deaths and ill-treatment of the detained should be brought to justice,' the organisation added.

Background

Nearly two weeks after launching anti-crime military 'Operation Clean Heart' on October 17, the Bangladeshi government acknowledged that 12 people have died in army custody and promised to investigate the deaths.

Soldiers conducting raids across the country have reportedly detained nearly 3,500 people and recovered more than 500 weapons. Bangladeshi authorities said they had deployed the army to help restore law and order as a crime wave soared after the government of Prime Minister Begum Khaleda Zia assumed power in October last year.

Members of various political parties including Bangladesh Nationalist Party and the main opposition Awami League are among the detainees. In particular two former ministers and key leaders of the Awami League, Saber Hossain Chowdhury and Sheikh Fazul Karim Selim are being held. Amnesty International has raised its concerns about their detention with the government.