Islamabad on ‘extremely’ high alert after Pakistan's tit-for-tat strikes on Iran

Islamabad is on “extremely” high alert after Pakistan launched strikes on separatist militants inside Iran on Thursday, in a retaliatory attack two days after Tehran said it struck the bases of another group within Pakistani territory.

Amid escalating tensions between the neighbours, a top Pakistani security source, as reported by news agency Reuters said anymore "misadventure" from the Iranian side will be met forcefully.

Pakistan conducted strikes inside Iran, targeting separatist Baloch militants, the Pakistani foreign ministry said.

At least nine people were killed in the strikes in the restive Sistan-Balochistan province, most of them women or children, Iran's official IRNA news agency reported.

Top updates on Pakistan-Iran fighting:

The United Nations and the United States have appealed for restraint after Iran and Pakistan traded deadly airstrikes on militant targets on each other's territory. UN chief Antonio Guterres called on the two governments to "exercise maximum restraint".

The military action between the heavily armed neighbours has further triggered tensions already heightened by the Israel-Hamas war.

Pakistan's retaliation comes days before the February 8 general elections. Shuja Nawaz, distinguished fellow and founding director of the South Asia Center of the Atlantic Council, said a weak caretaker government in Pakistan cobbled together to hold the elections may not be best equipped to deal with these complicated issues, allowing the military to take the centre stage yet again.

Pakistan's strikes came after Iran carried out raids on what it described as "terrorist" targets in Pakistan on Tuesday, killing at least two children.

Iran and nuclear-armed Pakistan often accuse each other of allowing militants to operate from the other's territory. However, cross-border operations by government forces have been rare.

White House national security council spokesman John Kirby said the United States was monitoring the situation "very, very closely" and was in touch with Pakistani officials.

India issued an official response saying that this is a matter between Iran and Pakistan. The ministry of external affairs said India has an uncompromising position of zero tolerance towards terrorism and understands actions that countries take in their self-defence.

China offered to mediate between the neighbours, both close economic partners of Beijing.

Pakistan's foreign ministry described Thursday's raids as a "series of highly coordinated and specifically targeted precision military strikes against terrorist hideouts" in Sistan-Balochistan.

Iranian media carried images showing severely damaged homes, with one video showing people gathered around a crater.

Condemning the action, Iran summoned Pakistan's charge d'affaires "to protest and request an explanation from the Pakistani government", foreign ministry spokesman Nasser Kanani said.

Jihadist group Jaish al-Adl (Army of Justice) has launched repeated deadly attacks on Iranian security forces in recent months, and Tehran has long alleged that it operates out of rear bases across the border.

Pakistan recalled its ambassador from Tehran and blocked Iran's envoy from returning to Islamabad.