Firefighters extinguish a fire at an animation studio in Kyoto, Japan, July 18, 2019. The death toll of an anime studio blaze in Kyoto on Thursday has risen to 33, with 36 others injured, some suffering from severe burns or bleeding, local police and rescuers said. (Kyodo News via Xinhua)

UNITED NATIONS, July 19 (Xinhua) -- United Nations (UN) Secretary-General Antonio Guterres said Friday he was "deeply saddened" over the death of at least 33 people inside a popular Japanese animation studio, in the city of Kyoto, following an arson attack that constitutes one of the worst mass-killings in the nation's history.

Guterres said that "in this tragic moment, the United Nations stands in full solidarity with the Government and people of Japan."

Japanese police have now identified the man suspected of carrying out the attack on Thursday morning. The man reportedly entered the Kyoto Animation (KyoAni) building, carrying cans of flammable liquid, which he poured across different areas of the film and graphic novel media business, before setting it alight.

According to news reports, witnesses to his arrest said he had alleged at the scene that the company had stolen some of his ideas. Around 70 people were in the building when the fast-moving fire began, and more than 30 were taken to the hospital. Many of those who died were reportedly found on a stairway trying to escape the flames.

"The secretary-general extends his condolences to the families of the victims and to the people and the Government of Japan. He wishes those injured a swift recovery," said a statement issued by the UN chief's spokesperson.

News reports say that dozens of people in Kyoto gathered outside the building on Friday, laying flowers and offering prayers.

The Kyoto Animation company has produced popular hand-drawn and computer animation programs including K-On and The Melancholy of Haruhi Suzumiya, and publishes graphic novels, many of which focus on the school life of teens. One of its recent series, Violet Evergarden, has been picked up by the global online screening giant, Netflix.