Dairy farmers blocked the three main supermarkets in Coleraine on Thursday evening.
Up to 200 farmers and 30 tractors took part in the protests, hours after the Stormont Agriculture Committee held an emergency meeting to hear of concerns on the crisis in the dairy sector over plunging milk prices.
Tesco was heavily targeted forcing Dale Farm milk delivery lorries away from the store. It is understood that a number of other lorries were also blocked from making deliveries.
The protest was still on going at 2am as dairy farmers were determined that there would be no milk delivered to the stores.
It is believed that the protests will continue over the coming weeks. Protests also took place in Limavady where farmers blocked the town and also in Strabane at the Asda Store.