(CNN) -- The Bangladesh Supreme Court has sentenced a prominent leader of the country's largest Islamist party to death for "crimes against humanity," the official Bangladeshi news agency BSS reported Tuesday.

The ruling in the case of Abdul Quader Mollah, who was the assistant secretary general for the now-banned Jamaat-e-Islami party, set off rioting in the streets and prompted the party to announce a two-day general strike across the country beginning Wednesday.

"The appeal filed by the state has been allowed, while the appeal filed on behalf of Abdul Quader Mollah has been rejected," Chief Justice Md. Mozzammel Hossain, who led a five-member Appellate Division bench of the Supreme Court, announced Tuesday.

In February, Mollah was sentenced to life in prison by a tribunal that convicted him of war crimes.

The panel was set up by the government to bring to justice some of those accused of atrocities during Bangladesh's 1971 war for independence. Its decision not to sentence Mollah to death set off huge protests earlier this year in Dhaka, the capital.

The demonstrations prompted parliament to change the law to allow the government to appeal rulings by the tribunal, which is what happened in Mollah's case.

The prosecutor said the latest court ruling left no room for further review, but defense attorney Abdur Razzak, who is also a Jamaat leader, said he would seek an appeal.

Law minister Shafique Ahmed said only clemency from the president could spare Mollah.

Attorney General Mahbubey Alam told journalists that the death sentence against Mollah was for his role in the brutal killings of a man, his pregnant wife and 2-year-old son in 1971.

Following the tougher sentence against him issued Tuesday by the top court, Jamaat supporters took to the streets, spurring unrest that left at least 10 people injured, CNN affiliate Boishakhi TV reported.

The station aired footage of cars on fire, including a police van in the seaside city of Chittagong.

Jamaat, a major ally of the main opposition party Bangladesh Nationalist Party (BNP), is a constant thorn in the side of the ruling Awami League.

The high court declared Jaamat's registration illegal last month, preventing it from taking part in the country's upcoming general election. The party has appealed the ruling.

Monday, Bangladesh's cabinet approved an amendment to an elections bill that bars anyone convicted of war crimes from participating in national elections.

Jaamat enjoys considerable support, particularly in rural areas. And periodically, it mobilizes its adherents in large-scale demonstrations in Dhaka to show its strength.

But it has faced pressure from the Awami League and progressive groups that point to Jammat's role during Bangladesh's struggle for independence from Pakistan.

Between one million and 3 million people were killed in the nine-month war.

The International Crimes Tribunal, the court set up by the government in 2010, has convicted several other top Jamaat leaders of crimes against humanity.

Jamaat acknowledges that it opposed Bangladesh's struggle for independence, but it has decried what it calls a smear campaign.

It has also questioned why the Awami League is only now pressing forward on war crimes trials when it didn't do so while in power during the 1970s and 1990s.

CNN's Farid Ahmed in Dhaka, Bangladesh, contributed to this report.