Sardari Lal Parasher recorded what he witnessed during partition in hundreds of feverish sketches. Then he buried the images in a trunk for the rest of his life.

The artist, from western Punjab, was a survivor of the blunt, bloody cleaving of the Indian subcontinent in 1947. As the train that would carry him from Lahore to Indian territory pulled in, an attendant pulled bodies off it and hosed it down, staining the platform red.

Once over the border, Parasher took a job as commandant of a refugee camp in the north Indian state of Haryana. He is said to have roamed the camp in the evenings, drawing with whatever he could find, even dirt, as he tried to stave off despair. One sketch, entitled Small Comfort, depicts women huddled together, expressionless but hunched in grief. Another, Defeated, is of a hooded woman face down on the ground. There is action too: men with batons raised over cowering bodies.

“These sketches remained in trunks throughout his life,” says Raju Parasher, his son. “They were never shown. They were never spoken about either.” It was not until 2004, after Parasher had died, that his children discovered the images, now displayed in the basement of a doctor’s clinic the family runs in south Delhi.

“My sister would set up a camera and ask my parents to tell me about that time,” Raju recalls. “My mother would remain silent. My father would open up occasionally, but not her. One day she had an outburst. She said: ‘It’s taken me a lifetime to forget. And now you’re asking me to remember? It’s not fair. It’s not fair at all’.”

Unwinding, by Sardari Lal Parasher

India will mark the 70th anniversary of its independence this month in the traditional way: a prime ministerial address from the ramparts of the Red Fort in Delhi, a flag-hoisting ceremony and a boisterous parade through the city.

Also traditional will be a near-total absence of any reference to the horrors that accompanied the birth of the world’s second most populous nation: the displacement of 15 million people and the orgiastic violence on both sides of the new border in which more than a million died.

“At the official level the horror has never been marked, never been commemorated,” says Urvashi Butalia, a publisher and writer. India has just one physical monument to those who suffered, and nothing in Delhi, where millions of refugees from modern-day Pakistan were housed.

No trace remains of the sprawling north Delhi camp where Amrit Sagar Bajaj arrived with his family in 1947, aged 12. “It was a dreadful phase,” he says. “We were looted and were even about to be killed. But we pretended to be Muslim and were saved.”

The official amnesia mirrors a private reluctance to remember among many of those who survived. “What is the use of remembering that bad phase?” says Bajaj, now living in a middle-class suburb where the camp once stood. “We are alive and that is more important.”

Asha Kohli was in college the first time her mother ever spoke of what they had witnessed in Lahore, a city the family fled at a day’s notice on 15 August 1947. “One day she told me: ‘They were bad times. We would go up to the roof of our house and see a fire here, a fire there’,” she recalls. “People were setting fire to Hindu homes. But then she would say that Hindus and Sikhs were setting fire to Muslim homes, too. It was a period of madness that she didn’t want us coloured by.”

The task of remembering is made harder by politics: relations between India and Pakistan are as poor as ever. Also, no single community emerged from partition as a simple victim.

“To commemorate something, you have to acknowledge that this violence didn’t leave behind easily identified aggressors and victims,” Butalia says. “It takes a lot of maturity to discuss this history without giving blame. They didn’t just do it to us. Everyone did it to everyone else, and we must never repeat it. I don’t think we’re able to face up to that.”

Things are slowly changing. The past two decades have seen a flourishing of history and literature examining the violence, particularly against women, that accompanied the creation of the two new states.

Parasher’s artworks will also soon be displayed in Amritsar, where the world’s first partition museum opened last year. “When partition happened it was probably too raw,” says the museum’s chief executive Mallika Ahluwalia. “Grieving was a luxury: there was no space and time to allow themselves to do that. They had to pick themselves up.

“Now there is a generation who were all children when partition happened. They are in the final years of their lives, and they desperately want to open up.

“This is really the last generation, and if we don’t capture their voices now, we will lose the opportunity.”

Muslim refugees near New Delhi attempting to flee India in September 1947. Photograph: AP

Ordinary citizens are also filling the gap. The Indian Memory Project, a website curated by Anusha Yadav, traces the history of the subcontinent through pictures and letters submitted by families – materials that might have sat on mantelpieces or in drawers for decades, unseen outside the home.

Yadav, a photographer and designer, set out in 2009 to collect images of weddings. She was inundated with pictures documenting the minutiae of subcontinental lives, many eradicated by its violent split. “After a year, one evening, the penny dropped,” she recalls. “This was a much bigger idea.”

Three weeks later, she set up a blog publishing the photos and pairing them with rich narrative accounts. The project has now evolved into a standalone site with over 175 entries, most infused by the epochal events of 1947.

“Indians don’t talk about pain. We’ve never been good at it. We get on with life because it’s a matter of survival,” she says. “Our attitude has been that horrible things may have happened to you – but tomorrow’s food won’t come by talking about it.”

The project is helping to change that, she says. “I’ve found that the more you tell stories, the more willing people become to talk.”