'Their [strikers'] action included intimidating other workers not to work and obstructing vehicles going in to and out of the site,' said Sha Tin divisional police commander, Albert Chan Kin-hung.

'This is considered illegal. They purposely obstructed traffic to the site. We will consider prosecution after studying the whole case.'

At about 10am, about 50 workers tried to prevent a coach loaded with workers from entering the Tung Lo Wan Hill Road construction site by blocking it with iron railings and standing at the entrance. The site is managed by Sun Hung Kai Properties.

Police ordered the striking workers not to obstruct the entrance, and tension escalated when additional officers arrived. When the strikers refused to back down, police began to clear the road by pushing them aside and pinning some to the ground.

The two strikers, aged 50 and 52, who were injured were sent to Prince of Wales Hospital, where they were in a stable condition.

Legislator and leader of the Confederation of Trade Unions Lee Cheuk-yan said the strikers, in a bid to show that they are sincere about returning to the negotiation table, would not visit construction sites over the next two days to urge workers to join them. The union has been backing the strikers.

Hopewell Holdings chairman Gordon Wu Ying-sheung criticised the striking bar benders' actions.

'This is totally wrong for them to stop others from working. They have no authority to deprive others of the right to work,' he said.

'If labour unions in any place become too powerful, the unemployment rate will be pushed upward. Businessmen will place their investment in places where the cost is low.'

But legislator Leung Kwok-hung, who took part in the protest, said the strikers were only trying to persuade the workers in the coach to get out and not work. In his view, the police action was not neutral.

'Security guards on the site should be the ones who deal with the striking workers, not police,' said Mr Leung. 'Police should not do the job of those guards who work for construction sites.'

Mr Chan disagreed, saying officers had always taken a neutral stance while maintaining public order throughout the strike. 'We fully respect the workers' right to strike and voice their demands, but they must obey the law,' Mr Chan said. 'They may not bar the entry of other vehicles to the construction sites and upset the public order.'

Secretary for Labour and Welfare Matthew Cheung Kin-chung urged workers to respect the law.