Jingchu and Rene Liu were considered as female leads. Following the box office success of Dragon Tiger Gate, Yen had announced SPL 2's development, along with plans to make a sequel to Dragon Tiger Gate. SPL 2 was now given another tentative title, Battling the Police Force (强战型警), and Yen also announced that the film would be written in a style similar to SPL. Yen had hoped the film would take part in the 2007 Cannes Film Festival and scheduled for a Labour Day release in 2007. The film was later retitled to Army Breaker (破军), which means destroying thousands of opponents in war. The film was given a budget of US$8 million and production was set to begin in Macau on September 2006. Filming The film was now given the working title City Without Mercy, and director Wilson Yip was forced to drop plans of shooting in Macau, due to the lack of extras needed for filming. Yip needed 250 extras for one scene, and decided to return to Hong Kong with his crew for filming. Filming in Hong Kong began on 13 November 2006, and the cast for the film had been finalised. Filming finally ended in March, and the film was now given its former title, Flash Point (導火線). After filming, it was revealed that the film had gone over budget. Fight choreography The fight scenes were choreographed by Yen, who combined mixed martial arts, an interdisciplinary form of fighting using elements of Brazilian jiu-jitsu, judo, karate, boxing, kickboxing and wrestling, with his trademark wushu and taekwondo. This method of fighting is something Yen considers to be the greatest development of martial arts in his lifetime. Yen admits that his challenge during filming was to communicate the essence of these techniques in the dramatics of the film. To ensure that the action scenes stood out, Yen not only hired martial artists from around the globe but also invited Collin Chou to join the cast. Festivals A promotional video highlighting Flash Point was shown at the 2007 Cannes Film Festival and the 2007 Hong Kong Film Awards. It also premiered at the "Midnight Madness" program of the 2007 Toronto International Film Festival in September that same year, at the Ryerson Theatre, with director Wilson Yip attending the premiere. Awards Reception Box officeFlash Point opened in Hong Kong on 26 July 2007 and in China on 9 August 2007.