A total of 23 persons were killed in an attack by gunmen in southwestern Pakistan.Radio Pakistan reported that 23 passengers were killed when gunmen opened fire on a bus in the southern Musakhel district of the country.Although details of the attack are not clear yet, Prime Minister Shehbaz Sharif's office strongly condemned the incident and requested a report on the incident.The Pakistani army has been waging an open war against militant groups in various parts of the country for several years.Source: Qatar News Agency