At least 30 people were feared dead in an arson attack on Kyoto Animation on Thursday morning (July 18).

The attack on the Kyoto city studio was Japan's worst mass killing since a suspected arson attack on a Tokyo building in 2001.

In Thursday's incident, police reportedly arrested a 41-year-old man who had shouted "die" as he poured what appeared to be petrol around the three-storey Kyoto Animation building.

Twenty people were confirmed dead and more than 10 were showing no vital signs, an official for the Kyoto City Fire Department said, using a term the authorities often use before a death has been confirmed by a doctor.

Several fans posted their condolences and concern on social media for the animators and the studio, which is known for producing several notable anime series.

Here are five things to know about Kyoto Animation:

1. Founded in 1981

Kyoto Animation, also known as KyoAni, was founded in 1981 by Yoko Hatta, a former employee at animation studio Mushi Productions, and Hideaki Hatta in Kyoto, Japan. The arson took place at one of Kyoto Animation's two studio buildings in Uji City, Kyoto, said anime website AnimeNewsNetwork.

In addition to its studios, the company also has a head office in Kyoto and a Tokyo office. Kyoto Animation also has an affiliated company, Animation Do, which has a separate production site.

2. All things anime

The company specialises in designing, producing and selling animation products. Kyoto Animation creates animation for television series, films and original video animations (OVAs).

The company publishes novels, comics and visual books, and also manages a school.

According to the company's website, they also have a store, named KyoAni Shop! Physical Store.

3. Notable works

Kyoto Animation gained prominence with a few notable works in the 2000s including The Melancholy Of Haruhi Suzumiya, K-On!, Lucky Star and Clannad.

The company is also well-known for works including Free!, Sound! Euphonium, A Silent Voice, Violet Evergarden and Liz And The Blue Bird in recent years which were popular in Japan and overseas.

The company was also involved in the animation process for renowned series like Crayon Shin-Chan and Doraemon.

4. Kyoto Animation Award

In 2009, the company announced an award programme and offered a monetary reward for manga, novel and script submissions. The studio also added an Animation Do Special Award in 2015.

Winners in the first year were given the chance of having their entries animated and released by the studio.

The animation awards, which took place every year from 2009 to 2017, was popular in animation circles, and websites such as Crunchyroll and AnimeNewsNetwork featured winning entries from the awards each year.

5. Fandom

The company, which has a loyal following in Japan and overseas, posts regularly on its YouTube channel, featuring animation snippets and interviews with voice actors.

The company and its affiliate Animation Do also organised a fan event day in 2015 including panel discussions with their directors, character designers and voice actors.

Following the fire, a music producer from the company, Suguru Yamaguchi, took to Twitter to inform fans that one of the directors, Naoko Yamada, was safe.

SOURCES: AnimeNewsNetwork, Crunchyroll, Kyoto Animation YouTube Channel, Kyoto Animation website