WHITING, Ind. (AP) – A BP refinery in northwest Indiana has seen its second major malfunction in three days.

The Times of Munster reports a leak happened at a pipe still on Wednesday morning at the Whiting refinery. The unit accounts for roughly one-quarter of the refinery's production capacity.

A BP spokesman says it's unclear how long repairs will take, but that the refinery is still making gasoline and other fuels. The facility is the largest in the Midwest.

Massive flames also shot up through flare stacks Monday. The BP spokesman says nobody was hurt and that production had been restored.

About 1,100 union workers have been on strike at the plant since early February. Those workers make up more than half of the refinery's workforce.