Hong Kong director Benny Chan says his upcoming film will feature stunning special effects that are in line with those in "X-Men Origins: Wolverine".

"It's basically China's answer to 'Wolverine'," Chan told reporters at a press conference in Hong Kong on Wednesday, where he was leading cast members to promote his sci-fi action film, "City under Siege".

The director says computer-generated scenes are likely to occupy half of the film.

"City under Siege" revolves around a circus clown and his colleagues who experience physical changes after accidentally ingesting a biological gas.

Aaron Kwok plays the clown, with Shu Qi as his love interest. Both stars have won top acting honors at the Taiwan Golden Horse Awards, known as the Chinese-language Oscars.

This will be Kwok and Shu's reunion after they worked together in the 1998 blockbuster, "The Storm Riders".

"City under Siege" also features "Rush Hour 3" actress Zhang Jingchu, as well as action star Wu Jing of "The Mummy 3".

The film is expected to open in Hong Kong next summer.