At least seven people were killed and three others injured in two consecutive explosions targeting passenger vehicles in Pakistan's northwestern Khyber Pakhtunkhwa province on Saturday morning, police sources said.

The first incident occurred at about 5:20 a.m. local time (0020 GMT) in Bannu district, where a vehicle was struck in a remote-controlled blast, the sources told Xinhua on condition of anonymity.

"During the evacuation and transportation of the injured to a hospital, a second blast occurred within a one-kilometer radius of the first explosion," the sources added.

Rescue teams shifted the bodies and injured victims to nearby hospitals for treatment, officials said.

Security forces and law enforcement personnel cordoned off the area, collected evidence and launched an investigation.

The sources said all those killed and injured belonged to the Hathi Khel tribe, whose members have been part of a local peace committee formed to counter the influence of militants belonging to the outlawed Tehreek-i-Taliban Pakistan (TTP) operating in the area.

While no group has claimed responsibility for the attacks, the sources have not ruled out the possibility that the victims may have been targeted because of their involvement in anti-militancy efforts, the sources said.

Authorities have launched a search operation and are conducting a thorough sweep of the area amid concerns that additional explosive devices could still be present.

Both President Asif Ali Zardari and Prime Minister Shehbaz Sharif have condemned the attacks and vowed to bring the perpetrators to justice.