Pakistan and Iran have both conducted strikes on each other’s territories in an unprecedented escalation of hostilities between the neighbors, at a time when tensions have risen sharply across the Middle East and beyond.
The two countries share a volatile border, stretching about 900 kilometers (560 miles), with Pakistan’s Balochistan province on one side and Iran’s Sistan and Baluchestan province on the other.
Both nations have long fought militants in the restive Baloch region along the border. But while the two countries share a common separatist enemy, it is highly unusual for either side to attack militants on each other’s soil.
Here’s what you need to know.
The opening salvo in this fast-moving sequence of events began Tuesday when Iran conducted strikes on Pakistan’s Balochistan province – killing two children and wounding several others, according to Pakistani authorities.
Iran claimed it had “only targeted Iranian terrorists on the soil of Pakistan” and that no Pakistani nationals were targeted.
But the attack sparked anger in Pakistan, which called the strike “an egregious violation of international law and the spirit of bilateral relations between Pakistan and Iran.”
Iran’s state-aligned Tasnim news agency said it had been targeting strongholds of the Sunni militant group Jaish al-Adl, known in Iran as Jaish al-Dhulm, or Army of Justice.
The separatist militant group operates on both sides of the Iran-Pakistan border and has previously claimed responsibility for attacks against Iranian targets. Its ultimate goal is independence for Iran’s Sistan and Baluchestan province.
Nuclear-armed Pakistan is majority Sunni – the dominant branch of Islam – while Iran and its “axis of resistance” is largely Shia.
Pakistan struck back two days later with what it called a “series of highly coordinated and specifically targeted precision military strikes” on several alleged separatist hideouts in Sistan and Baluchestan.
Announcing the strikes on Thursday, Pakistan’s Foreign Ministry said a number of militants were killed. At least 10 people — all Pakistani nationals — were killed, Tasnim reported, citing the deputy governor of Sistan and Baluchestan, who said authorities were investigating how those people had “settled in the village.”
Pakistan said it had for years complained that separatist fighters had “safe havens and sanctuaries” in Iran – and was forced to take matters into its own hands with Thursday’s strikes.
Pakistan and Iran’s struggle against separatists operating on either side of each other’s borders is not new.
Deadly clashes along the turbulent border have happened regularly over the years. Just last month, Iran accused Jaish al-Adl militants of storming a police station in Sistan and Baluchestan, which resulted in the deaths of 11 Iranian police officers, according to Tasnim.
What is highly unusual, however, is each side’s willingness to hit targets across those borders, without informing each other first. And all this is happening against the backdrop of Israel’s bombardment of Gaza, which has sent repercussions coursing through the region.
The larger regional conflict may have emboldened Iran to be more proactive in pursuing targets beyond its borders, experts say – especially as the United States walks a tightrope between de-escalating hostilities and flexing its own military might to deter further moves by Iran.
The day before the strikes in Pakistan, Iran launched ballistic missiles at Iraq and Syria, claiming to be targeting a spy base for Israeli forces and “anti-Iran terror groups.”
Meanwhile, heavy fighting continues between Israel and the powerful Iran-backed group Hezbollah across the Lebanon border; and the US is fighting Iran-backed Houthi rebels in Yemen, who have attacked ships in the Red Sea in the name of revenge for Israel’s assault on Gaza.
“If you don’t censure Iran and its proxies … then there’s no cost for them to continue to pursue those activities,” said Karim Sadjadpour, Senior Fellow at the Carnegie Endowment for International Peace.