Pakistan recalled its ambassador to Tehran on Wednesday, a day after Iran launched airstrikes on Pakistan that it claimed targeted bases for a separatist militant group.
Islamabad angrily denounced the attack as a "blatant violation" of its airspace and said it killed two children, while Tehran claimed it targeted bases for a Sunni separatist group.
Tuesday's strike in Pakistan's restive southwestern Balochistan province imperiled diplomatic relations between the two neighbors – Iran and nuclear-armed Pakistan have long regarded each other with suspicion over militant attacks. However, both sides appeared wary of provoking the other.
The attack also threatened to further ignite violence in a Middle East unsettled by Israel's ongoing war on Hamas in the Gaza Strip. Iran launched strikes late Monday in Iraq and Syria over an Daesh-claimed suicide bombing that killed over 90 people earlier this month.
In state media reports, which were later withdrawn without explanation, Iran said its paramilitary Revolutionary Guard targeted bases of the militant group Jaish al-Adl, or the "Army of Justice."
The group, which seeks an independent Balochistan and has spread across Afghanistan, Iran and Pakistan, acknowledged the assault in a statement shared online.
Six bomb-carrying drones and rockets struck homes that the militants claim housed children and wives of their fighters. Jaish al-Adl said the attack killed two children and wounded two women and a teenage girl.
Videos purportedly from the site, shared by the Baloch activist group HalVash, showed a burning building and two charred, small corpses.
Pakistan’s Foreign Ministry said it issued a strong protest late Tuesday with Iran's Foreign Ministry, and summoned an Iranian diplomat in Islamabad "to convey our strongest condemnation of this blatant violation of Pakistan’s sovereignty."
"The responsibility for the consequences will lie squarely with Iran," it said.
A senior Pakistani security official, speaking to The Associated Press on condition of anonymity as he was not authorized to talk to reporters, said Iran had shared no information prior to the strike.
He said Pakistan reserved the right to respond at a time and place of the country's choosing and such a strike would be measured and in line with public expectations.
"The dangerous precedent set by Iran is destabilizing and has reciprocal implications," the official said.
However, there were signs Pakistan was trying to contain any anger over the strike. The country's typically outspoken and nationalistic media covered the attack Wednesday with unusual restraint.
Jaish al-Adl was founded in 2012, and Iranian officials believe it largely operates in Pakistan.
The group has claimed bombings and kidnapped members of Iran's border police in the past. In December, suspected Jaish al-Adl members killed 11 people and wounded eight others in a nighttime attack on a police station in southeastern Iran. Another recent attack killed another police officer in the area.
In 2019, Jaish al-Adl claimed responsibility for a suicide bombing targeting a bus that killed 27 members of Iran’s paramilitary Revolutionary Guard.
Iran has suspected that Sunni-majority Pakistan is hosting insurgents, possibly at the behest of its regional arch-rival Saudi Arabia. However, Iran and Saudi Arabia reached a Chinese-mediated detente last March, easing tensions.
Pakistan, meanwhile, has blamed Iran in the past over militant attacks targeting its security forces.
Iran has fought in border areas against militants, but a missile-and-drone attack on Pakistan is unprecedented.
It remains unclear why Iran launched the attack now, particularly as its foreign minister had met Pakistan's caretaker prime minister the same day at the World Economic Forum in Davos, Switzerland.
After the Daesh bombings this month, Iran's Intelligence Ministry alleged the two bombers involved in the attack had traveled from Afghanistan into Iran through its southeastern border at the Jalg crossing - meaning they had traveled through Balochistan.
Pakistan's Balochistan province, as well as Iran's neighboring Sistan and Balochistan province, have faced a low-level insurgency by Baloch nationalists for more than two decades. They initially wanted a share of provincial resources, but later initiated an insurgency for independence.
Iran's attack on Pakistan came less than a day after Iranian strikes on northern Iraq that killed several civilians. Iraq recalled its ambassador from Tehran for consultations and summoned Iran’s charge d’affaires in Baghdad on Tuesday in protest. Iran separately struck Syria as well.