BEIJING (Reuters) - The parents of a 13-year-old boy who killed himself after playing a computer game for 36 hours are suing the game's licensed Chinese distributor for 100,000 yuan ($12,500), a Chinese newspaper reported on Thursday.

In 2004, Zhang Xiaoyi, from the northern Chinese city of Tianjin, jumped out of a window of his family's 24th floor apartment after playing Warcraft at an internet cafe.

His parents said in a legal writ that China Cyber Port Co. Ltd.'s failure to clearly warn of the inherent "dangers" of Warcraft -- a game produced by American company Blizzard Entertainment -- was responsible for their son's death, the Beijing Times reported.

"In America, Warcraft has a 'T' rating, where it's only suitable for children over 13... but we weren't aware," the paper quoted the parents as saying.

The parents said that China Cyber Port clearly knew that the "violent" and "bloody" content of Warcraft was unsuitable for minors.

They should have warned people about the risks of addiction and "taken measures to prevent players' from over-indulging themselves," they said.

Apart from seeking damages, the parents demanded that packaging and materials for all Warcraft games distributed in China refer to the game's "level of violence" and have clear, written health warnings.

"This is a public interest case," said Zhang Chunliang, an online addiction activist, in support of the parents.

"We are appealing to the country to build a healthy and complete game regulation system."

Computer and online gaming has exploded in China in recent years, with an estimated 13.8 million people taking part.

Amid growing concern that more and more young people are becoming hooked, China has issued a raft of regulations aimed at curbing excessive game playing at internet cafes and heavily fining owners that admit minors.