The gunmen who killed 14 members of Pakistan's security forces in the country's southwest earlier this week came from Iran to carry out the attack, officials said Saturday.
Some 20 people wearing uniforms from the paramilitary Frontier Corps stopped buses in Balochistan province, which were travelling along the coast to megacity Karachi, before gunning down the security officials.
Foreign Minister Shah Mehmood Qureshi said Pakistan had evidence the "terrorist outfits" that carried out the attack have "training and logistic camps inside Iranian areas bordering Pakistan".
Those killed included ten serving with the navy, 3 with the air force and one with the coastguard.
"We have shared this actionable evidence with Iran after due authentication and identified (the) location of the camps," Qureshi said.
Pakistan has created a new southern Frontier Corps with its headquarters in the southwestern city of Turbat to more effectively control its 950-kilometre long border with Iran, he said.
The construction of a fence along the border has already begun, he added.
Balochistan, which borders Afghanistan and Iran, is Pakistan's poorest province and the largest by landmass, with Islamist as well as ethnic Baloch separatists active there.
"We have clearly told Iranian authorities about the elements involved in the attack".
"Pakistan hopes they will take a swift action against the Baloch terrorist outfits," Qureshi said, referring to his telephone conversation with Iranian foreign minister Javad Zarif.
"We also hope that our Afghan brethren will... take necessary action because these Baloch terrorist outfits also have links in Afghanistan," he added.
"Zarif also assured me that his government would help Pakistan bring them to justice".
Pakistan Prime Minister Imran Khan will make an official visit to Tehran from Sunday, with topics of discussion to include ways to prevent recurrence of such incidents in future.
Qureshi said the two countries would set up joint border controls with "mutual consultations to ensure peace".
Pakistani security forces have been targeting insurgents in Balochistan since 2004, and have also been repeatedly accused by international rights groups of abuses there. The military denies the allegations.
Balochistan is also host to a number of major projects under the multi-billion dollar China-Pakistan Economic Corridor (CPEC).
The massive infrastructure project seeks to connect the western Chinese province of Xinjiang with the Arabian Sea port of Gwadar in Balochistan.
But it has also drawn its share of criticism, particularly by separatists who have long complained that residents do not receive a fair share of profits from the province's resources.
Violence in Pakistan has dropped significantly since the country's deadliest-ever militant attack, an assault on a school in the northwestern city of Peshawar in 2014 that killed more than 150 people -- most of them children.
But militants still retain the ability to carry out attacks, and analysts have long warned that Pakistan is yet to tackle the root causes of extremism.