Pakistan said on Thursday it had carried out strikes against militant targets in Iran, after Tehran launched attacks on Pakistani territory earlier this week.
Iranian state media reported three women and four children were killed in explosions in the country's southeast.
"This morning Pakistan undertook a series of highly coordinated and specifically targeted precision military strikes against terrorist hideouts in Siestan-o-Baluchistan province of Iran," a foreign ministry statement said, adding that a "number of terrorists were killed".
"This morning's action was taken in light of credible intelligence of impending large-scale terrorist activities."
The attack comes after Iran confirmed carrying out strikes against "a terrorist group" late Tuesday in Pakistan — an attack that Islamabad said killed two children.
"Pakistan fully respects the sovereignty and territorial integrity of the Islamic Republic of Iran," the foreign ministry said.
"The sole objective of today's act was in pursuit of Pakistan's own security and national interest which is paramount and cannot be compromised."
Iran's official IRNA news agency reported that "several explosions have been heard in several areas around the city of Saravan", quoting a provincial official.
Pakistan's foreign ministry on Wednesday denounced the "unprovoked and blatant breach of Pakistan's sovereignty" before recalling its ambassador from Iran and blocking Tehran's envoy -- currently in Iran -- from returning to the country.
The missile and drone attack targeted the Jaish al-Adl group in Pakistan, Iran's government said, after Tehran also launched attacks in Iraq and Syria against what it called "anti-Iranian terrorist groups".
Tehran and Islamabad frequently accuse each other of allowing militants to operate from the other's territory to launch attacks, but it is rare that official forces on either side engage.
The Iranian strikes add to multiple crises across the Middle East, with Israel waging a war against Hamas in Gaza and pro-Palestinian Houthi rebels in Yemen attacking commercial vessels in the Red Sea.
Associated Press