The incident took place at around 8.30 AM, police said.
The men with their faces covered and carrying iron pipes barged into the corporate office of Nitta Gelatin India Ltd and broke the glass walls using iron pipes and damaged cars parked inside the compound, Ernakulam Range IGP M R Ajit Kumar told reporters.
Some computers of the office were also destroyed by the attackers.
The men were clad in jeans and pants. One of them spoke in Malayalam and another in Hindi.
According to the security guard, the men were raising Maoist slogans. They also left behind a letter written in Malayalam stating that there is a need to take action against the company as it was causing pollution.
City Police commissioner has formed a team, including members from state intelligence, to jointly inquire into the incident.
