On the occasion of Viswakarma puja, the factory at Salap More locality under Bankra police station had handed over coupons to its 900 workers who would get a packet of biriyani from the eatery by showing the coupons.
The factory workers formed a long queue before the eatery and, after sometime, they got enraged as there was 'delay' in providing the biriyani packets to them, police said.
Eleven persons were arrested, police said.