WHITING, Ind. (AP) – Members of the United Steelworkers union have set up picket lines at gates outside the BP Whiting Refinery in northwest Indiana.

The union had notified BP Plc. that workers at the refinery and another refinery in Ohio would walkout early Sunday morning, joining a walkout that began at nine other refineries. The Times of Munster reports (http://bit.ly/1vb2Xeq ) more than 1,000 union members at Whiting are on strike.

The picket lines around the plant in Whiting began late Saturday night and continued Sunday.

A BP spokesman said that the company expects to continue operating with replacement workers and doesn't expect a significant effect on production.