The attacker had targetted the sports area of the armed forces' unit in the Shareefabad area of the tehsil.
Sources told VOA army officials were playing in a volleyball match when the bomb went off.
It said that eight soldiers succumbed to their injuries in hospital, taking the death toll to 11.
Later, the COAS visited CMH Peshawar to meet injured of the incident.More news: Two dead and 50 injured in SC train crash
The report said that the outfit noted that it was the second attack this month with more to follow.
Prime Minister Shahid Khaqan Abbasi strongly condemned the attack and expressed his grief over the losses of security personnel.
"No cowardly attack can deter us in pursuing our struggle against the menace of terrorism to its logical conclusion". Earlier the Pakistani Taliban militants had strong influence in most parts of Swat.
Daesh ruled the picturesque Swat Valley from 2007 until a massive military operation routed them from the area in 2009. Pakistan launched an operation in the tribal areas in June 2014, in which 3,500 alleged militants have been killed, according to the Army's data, which has not been independently verified.