At least 15 people, including eight security personnel, were killed and scores were wounded when a powerful bomb went off near an army truck in Quetta on Saturday.
Sarfraz Bugti, the home minister for Baluchistan, said the blast took place near a private hospital but its nature is still being investigated. Following the blast, officials have declared an emergency in the city, reported the Dawn news.
Pakistan's army press wing said the patrol was the target and there were at least seven civilians among the 15 killed.
"This terrorist attack was an attempt to mar Independence Day festivity".
The blast occurred at a bus stop in the provincial capital Quetta and the area caught fire soon after the explosion.
But The Bomb Disposal Squad said the blast was carried out by a suicide bomber.
"Our resolve won't succumb to any challenge", Bajwa was quoted as saying in an official tweet from a top military spokesman.
Daesh, a Takfiri terrorist group which mainly operates in the Middle East but has also established a branch in Afghanistan, has claimed several attacks in the Pakistani territory in the recent past.
Security forces cordoned off the blast site for investigations. Attacks have also been reported by groups related to the Taliban.
Balochistan has oil and gas resources but is afflicted by Islamist militancy, sectarian violence between Sunni and Shiite Muslims and a separatist insurgency.
The ISPR said the vehicle deployed on security duty was targeted in the attack.
Interviews with Baluchistan police and an internal police report viewed by Reuters described a Baluchistan-based militant network in the province's remote mountainous area of Wadh with 500-1,000 operatives led by a former military asset.