Bangladesh police stepped up security at the capital Dhaka's main prison where the authorities are expected to hang the leader of the country's largest Islamist party for war crimes Tuesday.

Motiur Rahman Nizami, leader of the Jamaat-e-Islami party, could be hanged Tuesday night after the country's highest court published the final judgement upholding his execution order.

"He (Nizami) will now be asked whether he would seek mercy to the president. If he does not, the government can execute him any time," Attorney General Mahbubey Alam said.

Nizami's lawyer told AFP last week that he would not seek any pardon as it would require him to admit crimes he was convicted of including mass murder, rape and orchestrating the killing of secular intellectuals during the 1971 war of independence.

Security has been stepped up outside Dhaka Central Jail, where Nizami was brought on Monday from a prison outside of the capital.

Three senior Jamaat officials and a leader of the main opposition Bangladesh Nationalist Party (BNP) have been executed since December 2013 for war crimes despite global criticism of their trials. All of them were executed at the Dhaka jail.

"Extra policemen have been deployed at the jail," Deputy Commissioner of Dhaka Metropolitan Police Mofizuddin Ahmed told AFP.

Nizami's execution would exacerbate tensions in the Muslim-majority country after a string of killings of secular and liberal activists and religious minorities by suspected Islamist militants.


Hacked to death

Since last month an atheist student, two gay rights activists, a liberal professor, a Hindu tailor who allegedly made derogatory comments against the Prophet Mohammed and a Sufi Muslim leader have been hacked to death.

Jamaat has said the charges against Nizami, a former government minister, are false and aimed at eliminating the leadership of the party.

Nizami took over as party leader in 2000 and played a key role in the victory of an Islamist-allied government in the 2001 general election.

The 1971 conflict, one of the bloodiest in world history, led to the creation of an independent Bangladesh from what was then East Pakistan.

Prosecutors said Nizami was responsible for setting up the pro-Pakistani Al-Badr militia, which killed top writers, doctors and journalists in the most gruesome chapter of the war.

Their bodies were found blindfolded with their hands tied and dumped in a marsh on the outskirts of the capital.

The trial heard Nizami ordered the killings, designed to "intellectually cripple" the fledgling nation.

He was convicted in October 2014 by the International Crimes Tribunal, which was established in 2010 by Prime Minister Sheikh Hasina's government and has sentenced more than a dozen opposition leaders for war crimes.

Rights groups say the trials fall short of global standards and lack international oversight, while the government says they are needed to heal the wounds of the conflict.

Amnesty International has called for an immediate halt to Nizami's execution, citing concerns over the fairness of the trials carried out by the tribunal.

In 2013 the convictions of Jamaat officials triggered the country's deadliest violence in decades.

Around 500 people were killed, mainly in clashes between Islamists and police, and thousands of Islamists were arrested.