Authorities in Pakistan say an official in the northwestern tribal region was shot dead and three local security personnel injured in an ambush by assailants in a mountainous area.

The June 1 attack that left Hameedullah Wazir dead was the eighth incident in the past two months involving targeted killings in North Waziristan, one of the mainly rugged, mountainous areas along the border with Afghanistan.

So far no group has claimed responsibility for these killings.

Wazir, who was in his early 30s, served as a political clerk in the political administration office in North Waziristan.

His father, Amanullah Wazir, had also worked for the government in the same area and was killed by Taliban militants several years ago.

Islamic militants had sanctuaries in the tribal region until a 2014 Pakistani Army offensive, after which most militants escaped to Afghanistan. They continue to carry out sporadic attacks.