Five people including four women were killed by the firing of unknown miscreants in two different incidents in North Waziristan on Monday, as a fresh wave of extremist violence rattles the Afghan borderlands, reported 24News HD TV channel.

Four women aid workers were gunned down when they were ambushed by two gunmen as they were driving through a village in North Waziristan district, according to local police chief Shafiullah Gandapur, who said just one passenger survived the assault.

"No one has claimed responsibility for the attack so far but it was surely an act of terrorism," he told AFP.

Gandapur said the aid workers were affiliated with a programme run by a local institute to develop household skills for women.

The incident and death toll was confirmed by Rasul Khan, another local police official.

All four women belonged to the Bannu division.

In another incident, unknown armed persons attacked a vehicle killing the driver, who identified as Zarwali, on the spot and abducted three of its passengers.

The so-called tribal areas along the Afghan border remain notorious for the availability of cheap guns, drugs and smuggled goods. The region was once home to a wide array of jihadist groups and was a focal point in the global war on terror.

Attacks have decreased in recent years following a series of military offensives against homegrown and foreign militants. In 2014, the army launched a massive operation to wipe out militant bases in North Waziristan aimed at ending a near decade-long insurgency that cost thousands of lives.

But militant groups are still able to carry out sporadic, isolated assaults.  A recent surge in attacks targeting security forces along the Afghan border has sparked fears that jihadist groups may be regrouping.