Clashes broke out at the manufacturing unit of Japanese air conditioner maker Diakin in Rajasthan's Neemrana when protesting workers, supporting the two-day nationwide strike, tried to enter the premises and hoist an union flag, the police said.
As many as 22 policemen were injured after the workers allegedly threw stones. The police also lobbed 35 tear gas shells and resorted to cane charging.
Union leaders claimed about 50 workers were injured in the police action.
The incident happened when 700 to 800 workers tried entering the company''s premises, additional superintendent of police Manish Tripathi said, adding that they had to use tear gas shells and force to disperse the gathering.
Mr Tripathi said a case would be registered and the ones involved were yet to be identified.
Two of the injured workers were critical and have been sent to Jaipur for treatment, state secretary of Centre of Indian Trade Union (CITU) Bhawar Singh Shekhawat said.
CITU leader Anil Yadav alleged that the company had hired bouncers who threw stones first.
In Jaipur, trade unions took out a rally and protested at ''Shaheed Smarak'' and condemned the police action in Neemrana.
Central trade unions have called for a two-day nationwide strike to protest against the government''s alleged anti-worker policies and unilateral labour reforms, apart from pressing for other demands.