Stacks of recently discovered photo film show military brutality against pro-democracy protesters in southwest South Korea 41 years ago in what became known as the Gwangju Uprising.

The footage was found by the daughter of the photographer, Katsuo Aoi, an Asahi Shimbun employee who died in 2017 at the age of 78.

His coverage of the incident, in which an estimated 167 people were killed and 78 others went missing, came by chance.

Aoi, who worked for the photography section of The Asahi Shimbun’s Osaka Head Office, and Tadaomi Saito, a reporter at the City News Section of the Osaka Head Office, were in South Korea to cover a feature story for the evening edition.

Akira Fujitaka, now 87, who was chief of The Asahi Shimbun’s Seoul Bureau at the time, contacted the journalists and asked them to head for Gwangju, 270 kilometers south of Seoul.

They took a bus and stayed in Gwangju from May 19 through 23, 1980.

President Park Chung-hee had been assassinated the previous year, ending the 18-year rule of the military junta. Authorities sent military units, including paratroopers, to crack down on the pro-democracy protests in Gwangju, which ended up isolated from the rest of the country.

Aoi entered the blockaded city twice with Saito to record the realities taking place there.

His newfound photos show soldiers dragging citizens from a bus and beating them, young men carrying an injured friend to safety, and caskets in a mortuary.

The film contains 247 photo frames, 57 of them in color, which was unusual for news photos of the time.

The photos, many of them strings of consecutive shots, show how students and other protesters fell victim to open violence.

Saito, who died in 2014 at the age of 71, said in his memoirs that on May 20, 1980, he saw dozens of taxis and buses turn on their headlights and honk as they joined a protest march along a main street of the city.

Troops shot tear-gas shells into one of the buses. When young men rushed outside to escape the smoke in the bus, soldiers pounced on them and beat them with clubs.

Aoi photographed the scene from high up in a building.

A while later, the building of Gwangju Munhwa Broadcasting Corp., which was airing statements of military authorities, went up in flames. Aoi also captured that scene on color film.

“Faced with strict censorship, South Korean news media of the time had no choice but to carry statements of the military verbatim to say the situation was a civil commotion by students and other citizens who had turned into a mob,” said Yuko Manabe, a professor of sociology with the University of Tokyo, who is well-versed in South Korea’s democracy movements.

“Foreign reporters in the city were the only ones who were able to report on what was going on,” she said.

The Asahi Shimbun and Kyodo News are the only Japanese media outlets known to have had reporters in Gwangju on May 19, 1980, the second day of the military crackdown.

“The days from May 19 through 23 fell on a key period, when a growing number of citizens were joining the protests, angered by the harsh violence of the troops,” said Yang Ra-yun, a research fellow with the Korea Institute of Contemporary Social Studies.

“Every single frame of the photos is valuable,” said Yang, who is well-versed in photographic records of the Gwangju Uprising. “In particular, I think no color photo was previously available of the broadcasting station building in flames.”

Aoi and Saito left Gwangju on May 23, followed a mountain trail to bypass checkpoints and hitched a ride on a farmer’s truck to Seoul. Saito filed stories by reading them over the phone, and Aoi sent photos from The Associated Press Seoul Bureau.

The two returned to Gwangju on May 27-28 after the military took control of the city.

On-site reports by Aoi and Saito were carried in the May 24 and May 29 morning editions in 1980 under the headlines: “Gwangju enraged: blood and destruction” and “Gwangju subdued in grip of the military.”

Eight of Aoi’s photos were used in the articles.

Mari Nakatsuka, Aoi’s daughter, discovered the unused shots while she was sorting out her father’s mementos at her home in Suita, Osaka Prefecture.

“My father braved difficulties in leaving these photos behind,” Nakatsuka, 53, said. “I hope they will turn out useful in a variety of ways.”

Manabe said foreign press coverage of the Gwangju Uprising drew public attention in the country in 2017 with the release of “A Taxi Driver,” a South Korean movie based on the true story of a German reporter and a cabbie who helped him in 1980.

The film contains a scene where people who have lost family members or close friends in the Gwangju Uprising ask the reporter to let the bare facts be known to the outside world.

“How foreign reporters risked their lives in covering the news and how citizens provided support for them in response give clues to modern-day issues about how we can support isolated people from outside their country,” Manabe said.