ISLAMABAD: A majority of militants fleeing operations in Pakistan's Mohmand and Orakzai agencies joined the Afghan chapter of the militant Islamic State (IS) group, Afghanistan's Ambassador to Pakistan Janan Mosazai said on Wednesday.

Addressing a seminar in Islamabad, the Afghan envoy said IS has become a major threat in the region.

About 60 to 70 per cent militants fleeing Pakistan during offensives in Mohmand and Orakzai went on to join IS in Afghanistan, Mosazai claimed.

He said terrorism was a common issue for both Pakistan and Afghanistan, and reiterated the Afghan government's commitment to not allow anyone to use its territory against Pakistan.

Mosazai said Afghanistan was committed to its policy of non-interference in neighbouring countries, including Pakistan.

Kabul wants good neighbouring relations with Pakistan as it is important for the economic prosperity of Afghanistan, the envoy said.

Mosazai said Kabul recognises the importance of the China Pakistan Economic Corridor, which he said will have a positive impact on the economy of Afghanistan as well.

Reports in the past suggested that militants fleeing military operations in different regions of Federally Administered Tribal Areas joined various terrorist groups in Afghanistan.

Security officials have warned against IS gaining a foothold in Afghanistan's eastern region, where the group reportedly murdered tribal elders, clashed with the rival Taliban, imprisoned families and enforced strict rules on women.

Afghanistan does not provide a natural constituency from which IS can recruit, meaning the group relies heavily on defections from existing insurgent outfits.

Backed by US drone strikes, Afghan security forces last year mobilised and eliminated multiple IS leaders along with dozens, if not hundreds, of militants.