Iran sought immediate explanation from Islamabad as death toll from Pakistani airstrikes this morning in border village of Sistan-Baluchestan province climbed to nine.

"Two men were also killed in the missile attack this morning in one of the border villages of Saravan, bringing the death toll to nine," the official IRNA news agency said quoting Alireza Marhamati, deputy provincial governor of Iran's Sistan-Baluchistan province.

Earlier Thursday, Pakistan's air force launched retaliatory airstrikes in Iran allegedly targeting alleged militant hideouts.

"This morning's action was taken in light of credible intelligence of impending large scale terrorist activities," the Foreign Ministry said in a statement.

"This action is a manifestation of Pakistan's unflinching resolve to protect and defend its national security against all threats," it added.