Regina police have arrested four people involved in a labour dispute at the city's Co-op oil refinery.
Police say four men from Saskatchewan face charges of mischief under $5,000 and disobeying a court order.
Unifor says the accused are Local 594 members who were on a peaceful picket line at one of the refinery gates.
Last month, officers arrested 14 union members, including Unifor's national president, after access was blocked to the plant.
Police say they're also investigating recent paintball damage to several residences and vehicles, which Co-op says are owned by company management.
More than 700 refinery workers were locked out in early December after the union issued a strike notice.
Saskatchewan Premier Scott Moe and Federated Co-operatives Ltd. have called on union members to stop their blockade and for police to enforce a court order limiting how long they can delay refinery traffic.
Moe said Monday that the blockade is illegal and restricting the flow of fuel to communities across the province.
Negotiations between the company and the union had resumed last week but broke down Friday and Unifor re-erected its barricades.
Unifor has said the company isn't bargaining in good faith and rejected a recent proposal that included $20 million in pension savings. Pensions are one of the key issues in the dispute.
"For Regina police to side with the employer and arrest lawful, picketing members is a disgrace and shows the unjust obstacles workers face simply to protect what they already have," Unifor president Jerry Dias said in a statement Wednesday.
The four men arrested are to appear in court in March.
This report by The Canadian Press was first published Feb. 5, 2020.