Glorious Mission Online was developed in collaboration with the Chinese military and released on Army Day.

It simulates an amphibious assault by Chinese forces on the Senkaku or Diaoyu islands in the East China Sea.

The release of the online version follows months of confrontation between Japanese and Chinese vessels in the disputed waters.

"Players... will fight alongside Chinese armed forces and use weapons to tell the Japanese that they must return our stolen territory," says a press release issued by Giant Interactive Group (GIG), the company behind the game.

The graphics show China's only aircraft carrier, the Liaoning, in action off the islands.

The players accompany invading Chinese troops in a series of explosive fire-fights with defending Japanese troops.

Earlier versions of the game were developed as training simulators for officers of the People's Liberation Army.

Some suggest that the military sees an opportunity to boost its image and profile with a new generation of nationalistic youths, who are attracted to war games.

"Most young boys, from the bottom of their hearts, want to be a soldier. They like to fight, they like to win," said company vice-president and game developer Gu Kai.

He suggested that Glorious Mission, with its openly nationalistic theme, would help army recruitment.

"On one hand it's a training tool, on the other hand it's about army recruitment," Mr Gu said.

"The army aims at recruiting university graduates, and gaming is the most popular culture among students," he told the AFP news agency.

Game of cat and mouse

Tensions with Japan have been inflamed by a continuing tense stand-off over the uninhabited islands, which are administered by the Japanese government.

Consumer boycotts and mass anti-Japanese demonstrations followed Japan's decision last September to buy the islands from their private Japanese owners.

A game of cat and mouse between Japanese and Chinese coast-guard cutters and other vessels has continued for months in the East China Sea.

The United States and independent analysts have warned that an accidental clash could inadvertently spark conflict given the inflamed passions on both sides.

More than a decade ago, Chinese officials banned video game consoles denouncing them as "electronic heroin".

The military now appears to have embraced the genre to help train its soldiers and to instil what it calls patriotic values in the hearts of the young, correspondents say.