The workers, members of the Maharashtra Kamgar Karmachari Sangathana, beat up manager Pradeep Sharma (36) in the park premises when they were prevented from joining duty for having dressed shabbily, said the police.

The incident took place at around 1.15 pm on Saturday, when the manager objected to the unkempt state of some workers, and told them that as per their job contract, they were required to be present for work neatly dressed, shaven and bathed, said Sub Inspector and investigating officer M P Bhoj of Borivli station.

On July 9, the management had even put up a notice warning employees not to dress shabbily after it received complaints that workers were turning up in an unkempt condition for the job. Some workers who, despite this order, reported for work shabbily dressed on July 10 were allowed into the park only after the union intervened andpromised that the incident wouldn't repeat itself. But when 12 workers came shabbily dressed again on Saturday, an irate Sharma told them that their's being a service industry, employees needed to be dressed presentably in keeping with the rules.

When Sharma prevented the workers from joining duty, the enraged workers threatened to strike work. However, Saturday being big business for the park, the management and clerical staff were asked to step in operate the rides.

At this point, 150-odd workers started shouting slogans, and then beat up Sharma in the park premises for about 30 minutes. The workers were led by union members Subodh Pawaskar, Dilip Vaiti and Jude Henricks among others, Bhoj informed. Fourteen others, who rushed in to help Sharma, were also injured in the melee. Nobody was seriously injured.

Bhoj registered a case of rioting against 26 of the workers, including the union members. They were arrested on Saturday night and later released on bail.