Dairy farmers staged a protest at the three main supermarkets in Coleraine on Thursday evening.
Up to 200 hundred farmers and 30 tractors blocked the three main stores in Coleraine.
Tesco was heavily targeted forcing Dale Farm milk delivery lorries away from the store. It is understood that a number of other delivery lorries were also blocked from making deliveries.
The protest - over falling milk prices - was still on going at 2am as dairy farmers were determined that there would be no milk deliveries.
It is believed that the protests will continue over the coming weeks.
They also took place in Limavady where farmers blocked the town and also in Strabane at the Asda store.