ISLAMABAD -- The Pakistani army said it dealt a new blow to the Taliban insurgency, capturing a top commander who once worked in Boston as a housepainter.

The white-bearded militant, Muslim Khan, had helped spearhead the group's two-year uprising in the Swat Valley in northwest Pakistan. With his choppy English, Mr. Khan also served as the Swat Taliban's chief spokesman for local and foreign journalists. He was arrested earlier this week with four other commanders in their Swat hideout, according to Maj. Gen. Athar Abbas,...