"According to the information we have received so far, there are around 15 casualties, people who were martyred, and around 40 people were wounded", Bugti said. Following the blast, officials have declared an emergency in the city, reported the Dawn news.
The army truck was passing by Quetta's Pishin Stop area of the city when it was targeted by the explosion.
Interior Minister Balochistan Sarfraz Bugti told ARY News that it was a huge blast but he can not say anything about the nature of blast.
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.
It cited army chief General Qamar Javed Bajwa as saying terrorists were trying to disrupt Monday's celebrations of 70 years of independence from Britain.
"Our resolve won't succumb to any challenge", Gen Bajwa said.
Mineral-rich Balochistan, where Gwader is located, has been plagued for decades by a separatist insurgency and sectarian killings.
Quetta, the provincial capital of Baluchistan province, has seen frequent attacks targeting government buildings and security forces, as well as civilians. Attacks have also been reported by groups related to the Taliban.
Bugti said, "It would be unfair to call the incident a security lapse". The entire area was cordoned off by police and security forces. However, military intelligence officials denied the Wadh network exists and the father of the alleged leader says his son is not involved with militants attacking the state.