Gurgaon: Violence in Maruti's plant at Manesar in Haryana Wednesday, in which a top company executive was killed, may be the result of a planned action by a section of workers and union leaders, police said Saturday.

"The Maruti Suzuki management at Manesar plant could not estimate the action plan of workers. Workers Wednesday first vandalised the control room and HR section of the plant and then set them on fire. In the incident, the HR general manager, Awanish Kumar Dev, who hailed from Ranchi, was killed. He got multiple fractures in his both the legs in workers' attack," said a police official.

In the action, about 100 employees, some of them managers and including two Japanese nationals, were injured and hospitalised.

According to the first information report (FIR), the problem first came to light around 8.30 a.m. Wednesday when a worker, Jiyalal, slapped supervisor Ramkishor Manjhi after his allegedly hurled a casteist abuse.

After hours long fruitless talks between management officials and union leaders, when the first A shift was over at 3 p.m., workers refused to leave the company premises. At the same time workers for B shift had already reached the factory.

"They stopped the work and took several managers and high ranked management officialS hostage. Each and every action was recorded on close circuit cameras installed there. Some union leaders may be aware of the facts, so they burnt down the main servers and more than 700 computers," said a senior official in the special investigative team (SIT), probing the case.

Deputy Commissioner of Police Maheshwar Dayal said, "Prima facie it looks that some of the people may have planned the (violent) action."

Police arrested 91 people and sent them to jail. Fifty-five main accused, including union leaders and members, are still on the run.