UN experts yesterday urged Bangladesh to carry out major human rights reforms to reverse "repressive trends" following the controversial election, which was boycotted by the opposition.

Prime Minister Sheikh Hasina was sworn in for a fifth term on January 11. Her ruling Awami League party won nearly three-quarters of seats in parliament, with allied parties and friendly independents making up nearly all the remainder.

Hasina has presided over breakneck economic growth in a country once beset by grinding poverty, but her government has been accused of rampant human rights abuses and a ruthless crackdown on dissent.

UN experts said they were "alarmed" at reports of "widespread attacks, harassment and intimidation of civil society, human rights defenders, journalists and political activists, which marred the recent elections".

The experts included the special rapporteurs on freedom of assembly, on the independence of judges, on human rights defenders and on freedom of opinion.

Special rapporteurs are unpaid experts mandated by the UN Human Rights Council as part of its fact-finding and monitoring mechanisms. They are independent and do not speak for the United Nations.

UN Human Rights Chief Volker Turk had previously said that mass arrests, threats, enforced disappearances, blackmailing and surveillance were all methods reportedly used by law enforcement officials in the months leading up to the January 7 vote.

He also lamented reported acts of political violence, including arson attacks allegedly committed by opposition groups, and said around 25,000 opposition supporters had been arrested.

The experts yesterday said they had written to the Bangladeshi government urging full investigations into the alleged numerous human rights violations.

They called for the immediate and unconditional release of all civil society and political activists detained without charge.

"We are alarmed by the dangerous decline of human rights, fundamental freedoms, and the rule of law in Bangladesh, eroding public trust in state institutions. This is also tarnishing the country's image and could endanger its social and economic development," they wrote.

They urged the government to prioritise human rights reforms and enable free political participation to restore public trust in democracy.

"This would also reassure foreign investors and send a clear message to the world that it is committed to upholding its international legal obligations."