Thousands of Butler County residents were without power Sunday afternoon as storms ripped through the region, but most have now had electric service restored, a West Penn Power spokesman said this morning.

About 3,000 customers were affected by the storms throughout Sunday afternoon and evening, said company spokesman Todd Meyers. The largest group of outages started at about 3:30 p.m. Sunday, when about 1,500 customers in the Portersville area lost power after an unexplained problem disrupted a power substation in the area. Meyers said the company couldn't identify the problem, but power was restored after about 20 minutes, when workers reset equipment at the substation.

The remaining outages were scattered across the county and due to strong winds pushing trees onto power lines, Meyers said.

The company worked overnight to restore service, and as of 9 a.m. today 123 customers remained without power. Customers in Allegheny and Center townships made up the bulk of those outages, according to information on the company's website.

The company said it expects to have power restored to all customers by late morning.