Iran's foreign ministry summoned Pakistan's ambassador to the country over a terrorist attack which killed 27 Revolutionary Guards last week, the Tasnim news agency reported on Sunday.
"The Islamic Republic of Iran expects Pakistan's government and army to seriously confront ... the terrorist groups active on its border with Iran," the foreign ministry said in a statement.
An Iranian official at the ministry called on Pakistan to quickly take the necessary steps for the identification and arrest of the attack's perpetrators.
The Sunni group Jaish Al Adl (Army of Justice), which says it seeks greater rights and better living conditions for the ethnic minority Baluchis, claimed responsibility for the attack on Wednesday.
Iran says militant groups operate from safe havens in Pakistan and have repeatedly called on the neighbouring country to crack down on them.
Pakistan's ambassador to Iran Riffat Masood said she would pass on the message, Tasnim reported.
Tehran had vowed revenge after the attack on elite Revolutionary Guard members near the border with Pakistan.
"The government of Pakistan must pay the price of harbouring these terrorist groups and this price will undoubtedly be very high," Major General Mohammad Ali Jafari, the commander of the Revolutionary Guards said at the funeral for the guards on Saturday, according to AFP.
Mr Jafari blamed Pakistan's army and Inter-Services Intelligence agency saying it harbours terrorists.
"The Islamic Republic of Iran will no longer observe the previous reservations and will directly act to counter such acts," Mr Jafari told mourners gathered at the city of Isfahan's Bozorgmehr Square, who chanted "Down with America!" and "We will never submit!".
The busload of Iran's Revolutionary Guards, between the ages of 21 to 52, was blown up by the Pakistani terrorist group on Wednesday in Sistan-Baluchistan, which has long been a flashpoint for conflict.
Jaish Al Adl was formed in 2012 as a successor to the Sunni extremist group Jundallah (Soldiers of God), which waged a deadly insurgency for a decade before it was severely weakened by the capture and execution of its leader Abdolmalek Rigi in 2010.
Iranian Supreme Leader Ayatollah Ali Khamenei has also linked the perpetrators of Wednesday's attack to "the spying agencies of some regional and trans-regional countries".
