According to a Paramount Pictures spokesman, a man allegedly under the influence of narcotics stormed on the set and swung an air conditioner unit at Bay's head, reports variety.com.
Bay, who was not injured, then ducked and avoided the blow from his attacker.
Earlier reports suggested that the director had been attacked by two brothers in Quarry Bay, where the movie is currently being shot, but Paramount strongly denied those reports.
"Contrary to several erroneous news reports made today, Bay did not get hurt in a fight on set," a statement from the studio said and added that police arrested the man and two companions and no one on the set was injured.
"Transformers 4", which has been filming for the past four months, will hit theatres June 27, 2014.
--IANS (Posted on 18-10-2013)