In July 1995, the Serbian actor Jasna Đuričić was 29 and juggling a theatre career in Novi Sad with the demands of her new baby daughter. Just over 100 miles away in the UN-declared safe area of Srebrenica, more than 8,000 men and boys were being slaughtered by Bosnian Serb death squads, right under the noses of the Dutch military peacekeepers assigned to protect them. It was the culmination of a sustained and brutal campaign of ethnic cleansing.

“We didn’t know anything then about what was happening in Srebrenica,” Đuričić says. “It was around five years later that there were rumours emerging about the mass graves, but we were a country isolated from the media. Everything was state-controlled. You couldn’t hear or see anything outside what they wanted you to see.”

Now she is playing a leading role in educating audiences about the genocide. In the gripping, gruelling Quo Vadis, Aida?, set in the hours leading up to the massacre, she plays a fictional UN translator named Aida Selmanagić (based loosely on Hasan Nuhanović, who wrote of his own experiences in Srebrenica in The Last Refuge). As thousands of terrified Bosniak Muslims seek sanctuary in and around the Dutch UN base, Aida tries to keep order and quell fears while ensuring the safety of her own family.

Her time is spent in an understandable state of heightened agitation. “It was very hard,” says Đuričić. “Aida is full of emotions but she has no time to stop and cry or think. Each time I had to save my tears. There was this tension in me always. There were physical problems, too. I don’t know how, but I overlooked the fact that I’d be running a lot, running all the time. We didn’t think about that!”

Although she is called upon to address crowds of extras, or to elbow her way through them, Đuričić found that the most challenging scene was one of the quietest. Near the end of the picture, Aida enters a hangar many years after the massacre to search among the bones and scraps of clothing laid out on the floor.

“We didn’t have any rehearsal for that because it was so delicate,” she says. “I didn’t know where the bodies were that I was looking for. There was an overlap between reality and fiction: the panic of myself, the actor who can’t do her job, and the panic of the character, Aida, as she looks for the remains of her loved ones. It is hard for her to recognise or remember something, such as a particular piece of clothing, after so many years. Was it red? Was it green?” Everything else in the film was choreographed meticulously. “But that’s the only take we did of that scene. I’ll never forget the silence on set. Complete silence.”

The film’s director, Jasmila Žbanić, has described Đuričić as “brave and progressive” for taking on the part. She shrugs at that description. “For me, it’s not brave. It’s normal. I’m an actor, it’s my job.” Could the role have jeopardised her future employment chances? “Maybe!” she laughs. “Who knows? Everything is possible, especially in this moment. Srebrenica is a rather touchy subject. When you mention it here, everyone gets so sensitive. There are people who believe there was no genocide, and there are those who know what happened and are talking about it. The whole world has the same problem now, I think, with rightwing rhetoric.” The significance of Srebrenica, she believes, is unmistakable: “It is the biggest wound in the Balkans.”

Her hope is that Quo Vadis, Aida? will accelerate the healing process. “It was the reason we made it. It is important young people see it because they don’t know anything about what happened, and what they do know is what the others have told them. The problem is: which side are those others on?” Her own daughter, who is studying in Berlin, phoned Đuričić straight after watching the movie. “She said, ‘I am here crying and thinking how to continue with my life.’” Anyone who sees the film is likely to share her sense of devastation.

Đuričić, who is 54, has had a busy stage and screen career in the Balkans. Her friend Dusan, who is helping out on translation duties today, has known her since they acted in a play 10 years ago. I ask him what she is like on stage, and he lights up. “Oh, she is full of this inner energy,” he says. “You can’t believe that the person who enters the theatre and grabs a cup of coffee is the same one up there under the lights. It’s still her, but something incredible happens.” Đuričić smiles bashfully. “Thank you, Dusan,” she says.

Her work has not been widely seen outside her home country, though she won the best actress prize at Locarno in 2010 for her performance as a woman jailed for killing her husband in White, White World, which brought Greek tragedy, as well as doleful musical numbers, to modern-day Serbia. The acclaim for Quo Vadis, Aida?, which is Bosnia’s submission for this year’s Oscars, should open up new international opportunities. “I think the film has a bright future,” she says. That goes for Đuričić, too.

• Quo Vadis, Aida? is streaming on Curzon Home Cinema from 22 January