ISLAMABAD: Iranian foreign Ministry lodged a strong protest and summoned Pakistan's Charge d'Affaires (CDA) Muhammad Zeeshan in Tehran on Wednesday, over the killing of eight Iranian border security guards by terrorists that allegedly crossed over from Pakistan.

"As the ambassador is away, our Charge d'Affaires Muhammad Zeeshan was called upon by the Iranian foreign office regarding concern over the tragic incident," a senior Pakistan diplomat told DawnNews via telephone.

Sources said Iranian senior officials, while interacting with the Pakistani CDA, demanded strict action against the culprits and strong security along the Pak-Iran border.

The Pakistani diplomat assured full cooperation in investigating the incident and said a probe into the incident has been launched by Pakistani agencies.

Border guard killings are under investigation, Pakistan assures Iran

Pakistan assured Iran on Wednesday that security agencies are actively investigating the incident.

Pakistan has also asked Iranian authorities to share any evidence they might have regarding this incident.

Foreign Office spokesperson Tasneem Aslam said that in the case the culprits have crossed over to Pakistan after committing the crime on Iran’s soil, they will be apprehended and brought to justice.

She added that Pakistan strongly condemns this act of terrorism and conveys sincere condolences to the bereaved families and the government of the Islamic Republic of Iran.

The statement came ahead of Iranian Foreign Minister Javad Zarif's two-day visit to Pakistan to discuss the crisis in Yemen and the Arab led coalition's airstrikes against Houthi rebels. Zarif will also discuss the state of bilateral ties, particularly the old sore spot in the relationship — the cross-border terrorism allegedly by Pakistan-based groups in the Iranian province of Sistan-Balochistan.

Know more: Rebels kill eight Iranian soldiers on Pakistani border

Eight Iranian border guards were killed in a clash with Sunni rebels who had infiltrated from Pakistan, Iran's official IRNA news agency reported on Tuesday.

“Armed terrorists entered Iran from Pakistan and clashed with border guards, killing eight soldiers before fleeing back to Pakistan,” Ali Asghar Mirshekari, deputy governor of Sistan-Balochistan province, told the news agency.

Balochistan has a large Sunni community and has seen repeated attacks by militants on the security forces of mainly Shia Iran.