Pakistan has launched retaliatory missile strikes into neighbouring Iran, less than two days after a similar Iranian attack inflamed relations between the states.

Pakistan said its strikes had hit "terrorist hideouts" in Iran's Sistan-Baluchestan, which borders Pakistan.

Iranian media reported that three women and four children had been killed.

Pakistan's hit comes after it was outraged by Iran's strike, which Tehran said was aimed at terrorist groups.

The reciprocal air strikes have occurred during a period of upheaval in the Middle East, where Israel is fighting the Palestinian group Hamas in Gaza and exchanging fire with Iran-backed Hezbollah in Lebanon, Iran-backed groups in Iraq and Syria are targeting US forces, and the US and UK have struck the Iran-backed Houthis in Yemen, who have been attacking shipping.

Pakistan and Iran have long accused each other of harbouring militant groups that carry out attacks from regions along their shared border.

But official military action between Pakistan and Iran on this issue is uncommon, and they typically maintain cordial, although fragile, relations.

On Thursday, Pakistan's foreign ministry confirmed its strikes.

It said Pakistan "fully respects" Iran's "sovereignty and territorial integrity" but its action on Thursday was "a manifestation of Pakistan's unflinching resolve to protect and defend its national security against all threats".

Pakistan had fiercely condemned Iran's strike on Tuesday, which Islamabad says killed two children.

It had warned Tehran of "serious consequences" for the "illegal" action, banned Iran's ambassador from returning to the country and also withdrew its own envoy from Pakistan.

Iran insisted its strikes were aimed only at Jaish al-Adl, an ethnic Baloch Sunni Muslim group that has carried out attacks inside Iran, and not Pakistan's citizens.

Earlier in the week Iran also attacked targets in Iraq and Syria - it said it had hit Islamic State and Israel's Mossad spy agency, both of whom it said had been involved in a bomb attack in the Iranian city of Kerman earlier this month which killed 84 people.

Analysts said Pakistan's response was not surprising and matched Iran's in being presented as a specific attack on insurgents,

"Pakistan's retaliation does raise the risk of escalation but it also provides an opportunity to step back from the brink. In effect, the two sides are even now," said Michael Kugelman, the South Asia director at the Wilson Centre.

"Islamabad had a strong incentive to try to restore deterrence, especially with Iran on the offensive around the wider region deploying direct strikes and proxies to hit out at threats and rivals. In effect, if Pakistan had held back, it would have faced the risk of additional strikes."

China, a strong ally of both nations, has called for both sides to show restraint and avoid an escalation.

Analysts say Iran's strikes this week were also likely driven by the current turbulent dynamics in the Middle East.

Tehran has said it does not want to get involved in a wider conflict but groups that it backs have been ramping up efforts to target Israel and its allies to show solidarity with the Palestinians.