A war crimes court in Bangladesh has ordered prison authorities to hang an Islamist leader, months after he was sentenced to death.

Abdul Kader Mullah of the Jamaat-e-Islami party was found guilty of crimes against humanity during Bangladesh’s independence war in 1971.

He could now be hanged at any time unless President Abdul Hamid or the Supreme Court intervenes.

Jamaat-e-Islami has called for a national strike on Monday in protest.

The special court has been trying Bangladeshis accused of collaborating with Pakistani forces and committing atrocities in 1971.

However, human rights groups say the war crimes tribunal falls short of international standards.

There are concerns that the execution of Mullah could trigger a fresh wave of violence across the country.

Mullah, who denied all the charges against him, was accused of being a member of the shadowy al-Badr force, which Jamaat is alleged to have created and which is accused of the kidnapping and murder of more than 200 Bengali intellectuals in the dying days of the war.

He was also accused of being behind a series of killings including massacres in the Mirpur area of Dhaka, which earned him the nickname of “koshai” or butcher of Mirpur and made him one of the more feared Jamaat leaders.

Mullah was convicted in February and jailed for life.

Thousands of protesters took to the streets demanding the death penalty, a move that prompted parliament to amend a law allowing the state to appeal against any verdict reached by the war crimes tribunal.

In September the sentence was increased by the Supreme Court to the death penalty.