Bangladesh's Supreme Court has rejected a final appeal by a Jamaat-e-Islami leader to overturn his death sentence for atrocities committed more than 40 years ago, clearing the last legal hurdle to his execution.

Chief Justice S K Sinha ruled that the review petition was "dismissed", upholding Mohammad Kamaruzzaman's original death sentence for genocide and torture of unarmed civilians during the 1971 war of independence.

Monday's ruling sparked clashes between Jamaat-e-Islami party supporters and police in Bangladesh's southeastern Noakhali district.

Al Jazeera's Tanvir Chowdury reported that one person was killed and another was injured in the Noakhali riots.

The party also called for a nationwide 48-hour strike from Tuesday to protest against the decision.

Kamaruzzaman was sentenced to hang in May 2013 by a domestic war crimes court for crimes including a mass killing at a site that has become known as the "Village of Widows".

An appeal court in November last year upheld the verdict, raising the prospect of his becoming the second Jamaat leader to be hanged for war crimes.

Abdul Quader Molla was executed in December, 2013.

'Notorious war criminal'

Lawyers for Kamaruzzaman, who is the third most senior member of the Jamaat, made a last legal appeal arguing that there were "serious discrepancies" in the testimonies of prosecution witnesses at his trial.

Secular activists who attended the brief court session were pleased with the verdict.

"We're happy. He is a notorious war criminal. We made several attempts during the 1971 war to capture him. But finally he is caught by the court," Anwar Hossain, who fought in the independence war, told the AFP news agency.

"We hope he'll be executed [in] the quickest time possible," he added.

The 62-year-old's only chance of avoiding the gallows will be if he is granted clemency by the country's president.

"He can now seek clemency from the president but it is up to him whether he wants to seek mercy or not," his lawyer Shishir Monir said.

Attorney General Mahbubey Alam told AFP that prison authorities would now ask Kamaruzzaman whether he would seek clemency from the president.

"If he refuses, he could be hanged at any moment," he said.

Molla was executed just hours after his review petition was rejected by the Supreme Court.

Under Bangladesh's law, the execution of the accused could be carried out within 21 days and before 28 days of the Supreme Court's upholding of a death sentence.

The upholding of Kamaruzzaman's execution order could worsen the ongoing unrest in Bangladesh, which has been hit by deadly protests over the opposition's bid to topple the government of Prime Minister Sheikh Hasina.

The country suffered its deadliest chapter of political violence in 2013 after the war crimes court handed down a series of death sentences to Jamaat leaders for their role in the 1971 conflict, which saw the then east Pakistan secede from the regime in Islamabad.

Opposition parties say the war crimes trials are politically motivated and aimed at settling scores, while rights groups say the trials have fallen short of international standards.

Hasina's secular government maintains they are needed to heal the wounds of the conflict, which it says left three million people dead.

Independent experts have estimated the death toll was much lower.

Source: Al Jazeera and agencies