More than 20 people were confirmed or presumed dead after a 41-year-old man stormed into a Kyoto animation production studio on Thursday and set fire to it by spraying a flammable liquid, local police and rescuers said.

In the fire that started at a studio of Kyoto Animation Co. in the city's Fushimi Ward around 10:35 a.m., 36 people were injured, 10 of them seriously, they said.

About 70 people were believed to have been working inside the three-story building at the time. The unidentified man was seen screaming "Die" when he torched the studio, according to the police.

The man, who was quickly apprehended, was being treated in hospital for burns on his face and chest, they said, adding he had told them he "threw a gasoline-like liquid."

The police said they had received information that a man carrying a container had bought gasoline in the morning at a gas station near the scene.

Kyoto Animation, known for short as "KyoAni" in Japan, has produced popular TV animation series including "K-On!" and "The Melancholy of Haruhi Suzumiya" (Suzumiya Haruhi no Yuutsu), which depict the daily lives of high school girls.

The company has animation studios in Kyoto and nearby Uji, where it is headquartered. The building in question is its 1st studio, according to the company.

People near the studio said they heard a series of explosions and saw black smoke billowing out of the building. People were later seen being carried out of the studio covered in blankets.

"A person with singed hair was lying down and there were bloody footprints," said a 59-year-old woman who lives nearby.

"I heard a bang. The black smoke rose and the burning smell was awful," said a hair salon manager in his 30s.

Firefighters managed to contain the fire around 3:20 p.m., about five hours after it began.

The Fire and Disaster Management Agency said it has dispatched officials to the site to investigate the structure of the building and why so many people died or were injured.

"In the face of the large number of casualties and the shocking sight, I am at a loss for words," Prime Minister Shinzo Abe said in a Twitter post.

Kyoto Animation, founded in 1981, has released a number of animations appealing to younger generations, particularly in the 2000s. Many fans have visited locations associated with the works.

In addition to anime production, the company's business has expanded to publishing light novels and training animators. It also sells its own products at its shop.

The death toll from the fire is one of the worst in recent years.

In 2001, a fire at a building in Tokyo's Kabukicho entertainment district killed 44 people. In another notable fire in 2008, 16 people died after a man set a video parlor ablaze in Osaka.