Iran's foreign ministry summoned Pakistan's ambassador in Tehran in protest over the killing of nine Iranian border guards by Sunni militants attacking from neighboring Pakistan, Iran's state news agency IRNA reported on Friday.

According to IRNA, the Sunni Muslim militant group called Jaish al Adl, or the Army of Justice, claimed responsibility for the attack on Wednesday in Iran's Sistan-Baluchestan Province.

"Iran expects Pakistan to take serious and essential measures to arrest and punish those terrorists responsible for the killing of our nine guards," IRNA quoted Foreign Ministry spokesman Bahram Qasemi as saying.

"The message was delivered to Ambassador Asif Ali Khan Durrani on Friday," he said.

Iran's southeastern Sistan-Baluchestan province, whose majority population is Sunni Muslim Baluch people like those across the border in Pakistan's Baluchistan province, lies on a major transit route for drug smugglers. It has long been plagued by unrest both from them and from separatist militants, Reuters reported.

Iranian President Hassan Rouhani also reported called on Pakistani Prime Minister Nawaz Sharif to prosecute the militants who killed the Iranian border guards.