Media playback is unsupported on your device Media caption Anbarasan Ethirajan reports on how the case unfolded, and divided a nation

Bangladesh's Supreme Court has rejected the appeal of an Islamist leader against his jail term for war crimes and sentenced him to death.

In February Abdul Kader Mullah, of the Jamaat-e-Islami party, was convicted by a special tribunal of crimes during the 1971 war of independence with Pakistan.

The life sentence imposed at the time sparked angry street protests.

His supporters said the charges were politically motivated but his opponents said that sentence was too lenient.

Analysis When the war crimes tribunal sentenced Mullah in February this year, it triggered a wave of protests led by youth activists. Thousands of people had gathered at a busy traffic junction in Dhaka demanding the death penalty. They said the sentencing was too lenient. The protests, which came to be known as Shahbag movement, spread to other parts of Bangladesh, rallying secularists across the country. The anger on the streets forced the government to amend a law to allow the state to appeal against any verdict or sentence passed by the tribunal - but this also drew criticism from rights groups Security was tight and the five-judge bench delivered the verdict in a packed court room, saying Mullah deserved the death penalty in connection with the killing of a family during a Pakistani army crackdown in Dhaka in 1971.

Thousands staged protests around the country demanding the death penalty for Mullah, who had been convicted of charges which included overseeing massacres during the bloody struggle for independence.

Double-edged appeal

The protests prompted parliament to amend a law which allowed the state to appeal against any verdict reached by the war crimes tribunal.

This meant that alongside Mullah's appeal against his verdict the Supreme Court also heard an appeal from the government which wanted a tougher sentence handed down.

Prosecutor Ziad Al Malum told AFP news agency that the decision to increase the sentence was approved by four to one at the court.

Defence lawyer Tajul Islam told the agency he was "stunned" by the verdict.

"This is the first time in South Asian judicial history that a trial court sentence has been enhanced by a Supreme Court," he said.

Local media reports cite Mullah's lawyers saying they will petition for this harsher sentence to be reviewed, but the attorney general has said there can be no appeal against a Supreme Court verdict.

Image copyright Getty Images Image caption There was considerable bloodshed and brutality during Bangladesh's struggle for independence against Pakistan

Correspondents say the only option left for Mullah would be to seek a presidential pardon.

Mullah's conviction and subsequent sentences handed down to other Islamist leaders by the tribunal over the last few months have unleashed a wave of unrest, pitting supporters of Jamaat, who accuse the government of pursuing a political vendetta, against pro-government groups.

Image copyright AFP Image caption News that Mullah had been given a death sentence was greeted with delight in some quarters

More than 100 people have been killed since January in the violence.

Following Tuesday's verdict clashes between Jamaat supporters and police broke out in Dhaka and in the southern city of Chittagong, with vehicles smashed and set alight.

The Islamists have called for a 48-hour shutdown - more violence is expected in the coming weeks, reports the BBC's Anbarasan Ethirajan in Dhaka.

Feared leader

Bangladesh independence war, 1971 Image copyright Getty Images Civil war erupts in Pakistan, pitting the West Pakistan army against East Pakistanis demanding autonomy and later independence

Fighting forces an estimated 10 million East Pakistani civilians to flee to India

In December, India invades East Pakistan in support of the East Pakistani people

Pakistani army surrenders at Dhaka and its army of more than 90,000 become Indian prisoners of war

East Pakistan becomes the independent country of Bangladesh on 16 December 1971

The war was devastating in its brutality but there are a range of estimates for the exact number of people killed - government figures estimate as many as three million died. Other studies suggest 300-500,000 perished. Key defendants Article that changed history Scars of war 40 years on Bangladesh confronts war crimes

This is just the first of a series of appeals against convictions handed down by the tribunal. Several other high-profile Islamist leaders have been sentenced by it including 90-year-old Ghulam Azam, the former leader of Jamaat-e-Islami, who was jailed for 90 years in July.

Abdul Kader Mullah, 65, was the assistant secretary-general of Jamaat and the war crimes tribunal found him guilty of five out of six charges, including murder.

He was accused of being behind a series of killings including large-scale 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.

The special court was set up in 2010 by the current Bangladeshi government to deal with those accused of collaborating with Pakistani forces who attempted to stop East Pakistan (as Bangladesh was then) from becoming an independent country.

But human rights groups have said the tribunal falls short of international standards.

Bangladesh government figures estimate more than three million people were killed during the independence war. Other researchers put the figure at between 300,000 and 500,000.