Iran has warned Pakistan that Tehran would hit militant bases inside the neighboring country if Islamabad does not confront Sunni insurgents who carry out cross-border attacks.
Iranian state media quoted the army's chief of staff, Mohammad Hossein Bagheri, as saying on May 8 that Tehran expects "the Pakistani officials to control the borders, arrest the terrorists, and shut down their bases."
"If the terrorist attacks continue, we will hit their safe havens and cells, wherever they are," he said.
Ten Iranian border guards were killed in April in an attack claimed by the Sunni militant group Jaish al-Adl.
Iran's Foreign Minister Mohammad Javad Zarif visited Islamabad early in May to discuss border security with Pakistani authorities. Pakistan assured Iran it would deploy additional troops along its border.
The porous frontier between the two countries has long been used by drug smugglers and militants, both of whom occasionally clash with Iranian security forces.
Jaish al-Adl that has carried out several assaults on Iranian security forces, claimed responsibility for attacks that killed eight border guards in April 2015 and 14 border guards in October 2013.
The militant group says its attacks are aimed at what it calls discriminations against Sunni minorities in predominantly Shi'ite Iran.
Based on reporting by AP and Reuters