BAGHDAD (Reuters) - Shi'ite militia forces executed 15 Sunni Muslims and then hung them by electricity poles in a public square in a town **rtheast of Baghdad on Wednesday, police said. A police ******r at the scene in Baquba, a mixed Sunni and Shi'ite town 65 km (40 miles) from Baghdad, said he believed the action was designed to keep Sunnis from supporting the Islamic State, an al-Qaeda offshoot which seized swathes of land in an advance through **rthern Iraq last month