Amidst other violent incidents rocking the troubled Khyber Pakhtunkhwa Province close to the Afghan border, three children were killed and two others injured in a powerful explosion, police said on Thursday.

The explosion occurred late Wednesday night in Ghwa Khwa locality of Lower South Waziristan, when an explosive device placed in a motorcycle exploded outside a residential building. An unknown man was said to have parked the motorcycle close to a local resident’s home, called Saddam Hussain, just prior to the explosion, officials said.

The victims were 15-year-old Shah Hussain, 7-year-old Sanaya bibi and 8-year-old Soreen bibi. Two other children who were injured in the explosion were promptly moved to Headquarters Hospital in Wana for treatment. They are reportedly stable.

The incident was followed by the police and security forces closing off the scene and conducting a thorough investigation to find out who is responsible for the attack. The authorities are looking at the possibility of making the explosion a link to militant activity, which has been resurgent in parts of the northwestern region of the country in the past few months.

The tragedy follows another incident in the province, in which militants reportedly attacked a cricket ground in Bajaur district with a quad-copter drone just days ago. The incident resulted in three children being injured, and renewed worries about the changing strategies of armed groups in the area.

Despite ongoing security operations, Khyber Pakhtunkhwa, particularly those adjoining Afghanistan, has seen an increase in violence and militant attacks. The recent explosion marks the tenuous security which has been compromised in the conflict and the increasing vulnerability of civilians, especially children, living in conflict zones.