More than 100 heavily armed insurgents briefly seized control of a major agricultural town in southern Somalia on Wednesday in a surprise attack that killed at least seven people, residents and officials said. The insurgents, firing rocket-propelled grenades and machine-guns, overpowered government soldiers and released an unknown number of prisoners in the dawn attack on Jowhar, 90 kilometers (56 miles) north of the capital, residents said. The attackers withdrew from Jowhar later in the morning, the Associated Press reported.