BIRMINGHAM, Ala. — A federal oversight board ordered the United Mine Workers of America to pay more than $13 million in compensation to an Alabama coal company where members have been on strike for more than a year, a ruling the union said Wednesday it would challenge.

The National Labor Relations Board said Warrior Met Coal Mining was due some $13.3 million for costs including increased security, damage repair and lost revenues from unmined coal, and individuals were due almost $30,000, mostly for damage to vehicles. Both amounts included interest.

The union, with roughly 1,100 members who went on strike on April 1, 2021, called the NLRB assessment an “outrageous” decision that it planned to fight.