By JOHNSON LAI | Associated PressTAIPEI, Taiwan -- After years of shooting big-budget movies in mainland China, actors Aaron Kwok and Tony Leung Ka Fai returned to their native Hong Kong to make a police thriller that they say captures the flavor of home.Leung and Kwok, in Taipei Monday to promote their new film, said they hope "Cold War" re-creates the success of 2002's "Infernal Affairs," the highly praised model for Martin Scorsese's "The Departed," which won four Academy Awards."Some viewers compare 'Cold War' to Hollywood productions," said Leung, who plays a senior police officer involved in a conflict with a colleague during their joint effort to resolve a crisis sparked by the hijacking of a police van."It was an invigorating experience shooting the film," the 54-year-old Leung told The Associated Press during a joint appearance with 47-year-old Kwok, his cool-headed police colleague in the production.Leung describes "Cold War" as "a movie full of Hong Kong flavor" that he says has not been seen since "Infernal Affairs." Since then, Leung said, "Hong Kong talent has left for the mainland to engage in co-productions, and our subjects have been limited because of the audiences' uncertain tastes.""Cold War" tackles the politics and power struggles within the police force, unlike the typical police versus gangster films, he said. Leung added that its release reflects the freedoms enjoyed by Hong Kong movie makers, particularly in comparison to those of their mainland counterparts.Kwok says the two police characters are dream roles for veteran actors like him and Leung. "We plunged into the roles," Kwok said. "We were not acting but rather actually engaged in a real battle."He said the film "depicts a high-level power struggle, but at the end their purpose is to protect the citizens and enhance public security, a theme unexplored before" in Hong Kong, he said.Kwok has starred in several China-produced big budget films, including "The Silver Valley" and "Bodyguards and Assassins."Leung was in China last year shooting martial arts epic "Taiji" when he was contacted by Sunny Luk and Leung Lok Man, who co-wrote the script of "Cold War" and also directed the film."I was enchanted by the role, a senior police officer whose son is among five policemen who disappear when their van is hijacked," he said."He sees the van's seizure as a challenge, an insult to the police, and hence conceives of the police action not because of a specific concern for his son but because he considers every one of the policemen as his own son or daughter," he said."Cold War" was released last week in Hong Kong to full houses. It opened Monday in Taiwan.