Islamabad, April 8 (IANS): Pakistan on Wednesday assured Iran that security agencies were actively investigating an incident in which rebels from Pakistan killed eight Iranian border guards.

Eight Iranian border guards were killed on Tuesday in a clash with Pakistan-based Sunni rebels.

"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 Iran's Sistan-Balochistan province said.

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

She added that Pakistan strongly condemned this act of terrorism.

The statement came ahead of Iranian Foreign Minister Javad Zarif's two-day visit to Pakistan starting on Wednesday to discuss the crisis in Yemen and the Saudi Arabia-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.