Malakand Deputy Inspector General (DIG) Syed Fida Hussain said the suicide bomber attempted to enter the police station but was stopped by officers on duty.
"The suicide bomber was attempting to enter Kabal Police Station, but officers on duty stopped him," the DIG told Geo News.
He said the attacker detonated the explosives near the main gate of the police station.
Assistant Commissioner Kabal confirmed that seven people were killed and 15 others were injured in the blast.
Swat District Police Officer (DPO) Muhammad Omar said the explosion occurred near Kabal Chowk.
He added that a human head recovered from the scene was believed to belong to the suspected suicide bomber.
According to the DIG, a protest by local youths was also taking place in the area when the explosion occurred.
Police and rescue teams reached the site after the blast, while an investigation into the incident has been launched.
