However no one was hurt in the incident.
Kok, a Selangor state exco member, will be holding a press conference this afternoon on the matter.
In recent days, Kok has come under fire from several quarters for her remarks on the low quality of food given to her while she was under a week-long Internal Security Act detention last week.
Kok was arrested under the ISA on Sept 12 for raising Islamic issues. She was released on Sept 19.