Singapore has banned an Xbox 360 video game because it contains a sex scene between a woman and a female alien, the city-state's censors said Thursday.

"Mass Effect," a futuristic space adventure published by Microsoft Corp., has been banned because of "lesbian intimacy," Chetra S., deputy director of the Board of Film Censors, in a statement.

Players can engage their avatars in a variety of sexual encounters during the game, though none between men or between men and male aliens, according to reports on several blogs.

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The human-alien duo are depicted kissing and caressing each other in a sex scene that The Straits Times English-language newspaper in Singapore reported ends with the alien saying, "By the gods, that was incredible, commander."

A Microsoft spokesman in Singapore said Microsoft respected Singapore's decision to ban the game, which is to launch globally on Nov. 20.

"'Mass Effect' features realistic content and interactions in the context of the science-fiction story line," Ian Tan, marketing communications manager for Southeast Asia said. "The game takes a mature approach to various relationships amongst characters throughout the game and the content in question is another dynamic of that."

Chetra, of the censors' board, said Singapore's video games industry is largely self-regulated, with game importers responsible for declaring to the censorship board that the game content falls within a set of guidelines.

"This helps to ensure that games are suitable for a general audience and do not feature exploitative or gratuitous sex and violence, or denigrate any race or religion," Chetra said.

Other video games that have been banned this year include "God of War II," for nudity, and "The Darkness," for "excessive violence and religiously offensive expletives," Chetra said.

Chetra said the city-state's Media Development Authority, which oversees the censors' board, will introduce classification for video games next year, a move that could allow games such as "Mass Effect" to be passed under a mature classification.

Authorities in Singapore have banned gay festivals and censored gay films, saying homosexuality should not be advocated as a lifestyle choice.

Under Singapore law, gay sex is deemed "an act of gross indecency," punishable by a maximum of two years in jail. Despite the official ban on gay sex, there have been few prosecutions.