A pair of brothers, ages 27 and 28, approached Bay on the set and demanded HK$100,000 (about $12,900), according to the report. One of the brothers allegedly assaulted Bay and three police officers who tried to intervene.
The younger brother was arrested for blackmail and assault and the older brother was arrested for assault, a police spokesperson told Reuters. A third man was also arrested, but it's unclear why.
Initial reports claimed that Bay declined treatment for injuries to his face, but a spokesperson for the director denied this.
"Contrary to several erroneous news reports made today, Bay did not get hurt in a fight on set," Bay's spokesperson said in a statement, according to Vulture. "The production company did have a bizarre encounter with a man (allegedly under the influence of a narcotic substance) who was wielding an air conditioning unit as a weapon. The man, who had earlier accosted several other crew members, rushed onto the set in Quarry Bay and swung the air conditioning unit directly at Bay's head. The director ducked and wrested the air conditioner from his attacker, preventing what could have been a serious accident."
Police and the production company's security team subdued the men and no one was injured in the incident, according to the statement.
Filming resumed promptly, and the incident is under investigation.