AT least nine people have been killed after Pakistan pounded Iranian "terrorist hideouts" in a wave of revenge missile strikes.
The airstrikes on the Sistan and Baluchestan province on Thursday morning come days after an Iranian drone strike left two children dead.
The latest strikes add to exploding tensions in the Middle East as the Israel and Hamas war rages on and Iran-backed Houthi rebels cause chaos in the Red Sea.
A deputy governor of the Sistan and Baluchestan province, Ali Reza Marhamati, said the dead from Pakistan's airstrikes included three women and four children.
Militant group HalVash shared images online that appeared to show the remains of the munitions used in the attack.
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It said a number of homes had been struck in the city of Saravan.
Pakistan's Foreign Ministry described their attack on Iran as a "series of highly coordinated and specifically targeted precision military strikes".
"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."
A senior Pakistani security official said the military was on "extremely" high alert and would meet any "misadventure" from the Iranian side forcefully.
Earlier this week, Iran attacked targets inside Pakistan with bomb-carrying drones and rockets.
Pakistan's Foreign Ministry claimed two children were killed in the “unprovoked violation” of the country’s airspace while others were injured.
Iran's state media said its warped terrorist army the Revolutionary Guard carried out the strikes on Tuesday evening - but later withdrew the reports.
Reports said they targeted bases belonging to the militant group Jaish al-Adl, who also have a presence in Iran itself.
The group raged on Tuesday that six bomb-carrying drones and rockets struck homes belonging to the militants, their wives and children.
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They claimed two children had died in the ambush and two women and a teenage girl were injured.
Chilling footage reportedly taken near the site - shared by HalVash - appeared to show a burning building and two small bodies.
Pakistan had slammed the airstrikes - and warned that Iran could face "serious consequences" following the "completely unacceptable" escalation.
China urged both countries to show "restraint" after the strikes.
On Thursday, Beijing said it was willing to mediate between nuclear-armed Pakistan and neighbouring Iran.
"The Chinese side sincerely hopes that the two sides can exercise calm and restraint and avoid an escalation of tension," foreign ministry spokeswoman Mao Ning said.
"We are also willing to play a constructive role in de-escalating the situation if both sides so wish."
Several insurgent groups operate in Iran and Pakistan - including the Jaish al-Adl Sunni separatist group that was targeted by Tehran in its own strike.
They all want an independent Baluchistan for ethnic Baluch areas in Afghanistan, Iran and Pakistan.
Pakistan's Baluchistan province, as well as Iran's neighbouring Sistan and Baluchestan province, have faced insurgencies from Baluch nationalists for more than two decades.
But missile and drone strikes are unprecedented.
And analysts warned the escalation in tensions between Pakistan and Iran could quickly get out of hand.
Asfandyr Mir, a senior expert on South Asia security at the US Institute of Peace, said: "Iran's motivation for attacking Pakistan remains opaque but in light of broader Iranian behaviour in the region it can escalate.
"What will cause anxiety in Tehran is that Pakistan has crossed a line by hitting inside Iranian territory, a threshold that even the US and Israel have been careful to not breach."
It comes after the US launched a fourth round of strikes against Houthi rebels in just under a week after another cargo ship was struck.
On Wednesday night, an American cargo ship sailing under a Marshall Islands flag off the Yemen coast was damaged - with the furious rebel group vowing "more attacks are coming".
The US swiftly hit back with strikes targeting several sites that were prepared to launch further assaults.
Washington said it will re-designate the group as "global terrorists".
The new designation will require US financial institutions to freeze Houthi funds and its members will be banned from the US.
The Yemeni Armed Forces warned that "more attacks are coming" in retaliation for US and British attacks on Houthi assets.
