Islamabad: Pakistan Prime Minister Imran Khan Sunday arrived on his first-ever two-day official visit to Iran to promote bilateral relations, amid tensions in ties over the killing of 14 Pakistani security personnel by militants who allegedly came from the neighbouring country.

Unidentified gunmen donning uniforms of paramilitary soldiers Thursday massacred 14 security personnel, mostly from the Pakistan Navy, after forcing them to disembark from buses on a highway in the restive Balochistan province.