Director Michael Bay has been attacked in Hong Kong while filming the fourth instalment in his Transformers movie franchise.
The American film-maker was approached by two brothers surnamed Mak, aged 27 and 28, who demanded HK $100,000 (€9,433), police said.
The older brother attacked Bay, leaving the director with injuries to the right side of his face. Local media said he refused to go to hospital.
The 28-year-old subsequently launched an alleged assault on three police officers who attempted to intervene.
According to a local newspaper, the incident caused a "huge disturbance" to filming, but work on the set has now resumed following today's attack.
It is rumoured that the men were angry after missing out on disturbance fees paid by the crew to local business owners who were likely to be affected by filming.
The younger brother was arrested on suspicion of blackmail and assault, and his sibling was arrested on suspicion of assault. A third man, named Chan, was also arrested at the scene. All three are currently in police custody.
Studios are increasingly filming parts of their big blockbusters in China, exploiting the ever-increasing box office potential of the Asian territory.
This year's Iron Man 3, which had special scenes featuring Chinese actors, took $121m (€88m) in China, making it the Marvel film's biggest market outside of the US.