Unifor says the accused are Local 594 members who were on a peaceful picket line at one of the refinery gates.
Saskatchewan premier says the illegal blockade is restricting the flow of fuel to communities across the province.
Court found Unifor disobeyed interim injunction limiting time members can hold up traffic going in and out of the Co-op refinery.
Union’s tactic is an attempt to force the company back to the bargaining table.
A tear measuring almost 18 cm long triggered the initial explosion and subsequent smaller ones.
A group of Canadian manufacturers have formed a purchasing co-operative that will allow members to leverage their buying power for products commonly used in plants.