Every day since early February, hundreds of thousands of demonstrators have massed at an intersection in Bangladesh's bustling capital city. But unlike the Tahrir Square and Occupy Wall Street movements, they're not calling for the overthrow of the government or greater economic equality.

The rallies, led by youths and fueled by social media, are demanding the death penalty for those who took part in war crimes during Bangladesh's bloody battle for independence from Pakistan more than four decades ago.

And in the fourth most populous Muslim country in the world, the peaceful movement is also trying to achieve something remarkable: a ban on extreme fundamentalist parties.

"It's a revolution. A social revolution," says Dhaka resident Shaon Tanvir. "They have been using social media very effectively. A couple of hours' notice, and hundreds and thousands of people turn up."

Parents bring their children, their faces painted red and green in the colors of the Bangladeshi flag. Housewives pack lunches for the demonstrators. Passing motorists honk their horns and flash thumbs-up signs.

"In Bangladesh, we've seen power struggle among the political parties over the years. Now we see the strength of the young generation without any party affiliation," said a college teacher, Saiful Islam, who joined the sit-in.

"They are not violent, but no parties can defy them or ignore the demands."

The genesis

During the nine-month war in 1971, between 1 million and 3 million people were killed, and hundreds of thousands of women were raped. Many of the atrocities were committed by Pakistani forces and their civilian collaborators.

"When the fighting was over, there were vultures almost too fat to fly, and Bangladesh was a land with few of the sinews of nationhood left unsevered," the National Geographic said in a piece soon after the birth of the country.

In 2010, Bangladesh set up a court that it called the International Crimes Tribunal to finally bring to justice those it accused in the massacre.

So far, the court has indicted 10 people. Seven of them are top leaders of Bangladesh's largest Islamist party, Jamaat-e-Islami.

Jamaat acknowledges that it opposed Bangaldesh's struggle for independence. But it has decried what it calls a smear campaign. It has also questioned why the ruling party, 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.

In January, the court tried its first case and convicted Abul Kalam Azad, an expelled Jamaat member who is at large. Azad was sentenced in absentia to death by hanging. The cleric is believed to be hiding in Pakistan.

Another Jamaat leader, former lawmaker Delwar Hossain Sayedee, was found guilty Thursday on eight counts -- out of 20 charges -- involving killings and rapes, and was sentenced to hang.

Sayedee, a two-time member of Bangladesh's parliament, responded that the court "has done injustice" to him. His lawyer, Abdur Razzak, said the sentence would be appealed.

Angry Jamaat supporters clashed with police in demonstrations against the verdict nationwide, while the party blasted the trial as "politically motivated." But Bangladesh law minister Shafique Ahmed said the death sentence reflected people's expectations.

"It's established the rule of law, and the trial process is being continued maintaining international standards," the law minister said.

Widespread demonstrations also followed the life sentence handed down to Abdul Quader Mollah, Jamaat's assistant secretary general, on February 5. That's when the rallies at Dhaka's Shahbag intersection began, as those who thought the sentence was too mild gathered at the intersection to protest.

"For four decades, we have remained quiet with the hope that one day these war criminals will be sentenced to death," said Shoaib, a student of Dhaka University, in a CNN iReport by Aminul Islam Sajib. "We cannot accept their lifetime imprisonment."

The scene

The demonstrations started with a handful of bloggers and college students who took to Facebook and Twitter to ask others to join in the outrage.

Soon the masses swelled -- and cut across economic, religious and ethnic divides.

Fathers stop by with young sons in tow. Office workers show their support at the end of the workday. Rickshaw pullers donate part of their day's earnings for supplies. Even the Bangladesh national cricket team has made an appearance.

The protesters have renamed the intersection "Projonmo Chottor" (New Generation Circle).