The Star reported that the incident occurred near the gate of the main entrance at about 3.30am.
According to a source, a policeman on sentry duty saw two men on a motorcycle, suspected to be gang members, trying to hang a banner on the gate.
The duo fled on their motorcycle when the sentry approached them. However, before leaving, one of them threw a Molotov cocktail at the entrance, that left a black scorch mark on the road.
Police later found a banner with the phrase “last warning for PDRM”.
It is believed the incident could be related to a recent crackdown on gang members in the state.