At least five people were killed and 20 were injured in a blast on Chaman's Mall Road on Monday, Assistant Commissioner Zakaullah Durrani said.
The wounded have been shifted to the Civil Hospital.
According to police inspector Muhammad Mohsin, unidentified miscreants had planted an improvised explosive device in a motorbike that was parked on the roadside. Durrani said that the explosion targetted a vehicle of the Anti-Narcotics Force.
Window panes of several shops and houses in the vicinity were shattered due to the impact of the explosion.
Prime Minister Imran Khan, in a statement posted on the PM Office's Twitter account, condemned the incident and expressed grief for the lives lost.
Chaman is considered a sensitive town in Balochistan as it shares a border with Afghanistan's volatile Kandahar province. In March this year, at least nine people were injured in an explosion near the Levies Lines of the town. The attack targetted Levies Risaldar Maj Naseebullah, who remained safe.
Balochistan has recently seen an increase in terrorist attacks. Last month at least one person was killed, while seven were injured in an explosion in a bazaar in Turbat that was also caused by an IED planted in a motorbike.
Earlier in May, seven soldiers, including a junior commissioned officer, were martyred in a bomb blast and an exchange of fire with militants.
Six of the soldiers were martyred in Bolan district when an improvised explosive device went off near the vehicle in which they were travelling. One other was martyred in an exchange of gunfire with militants in Makran district, sources had said.
In April, two Pakistan Army soldiers were martyred and two others injured in a bomb blast that took place in Toba Achakzai area of Qila Abdullah, a district bordering Afghanistan.