Pakistan says two children were killed and three others injured in strikes by Iran on Tuesday, the third country targeted by Tehran this week.
Iran said it hit two sites linked to the militant group Jaish al-Adl, according to a news agency affiliated with the country’s military.
Pakistan called it an “illegal act” and warned that it could lead to “serious consequences”.
Iran has also attacked sites in Iraq and Syria this week.
Iran said those attacks were “targeted” operations to punish those who breach its security.
A missile attack by Iran on Pakistan is near-unprecedented.
Tuesday’s strike hit a village in the vast south-western province of Balochistan, which borders the two countries.
Pakistan’s foreign ministry condemned the “unprovoked violation of its airspace by Iran” and lodged a protest with Tehran.
It called the incident “completely unacceptable”, adding that it was “even more concerning that this illegal act has taken place despite the existence of several channels of communication between Pakistan and Iran”.
China on Wednesday urged Pakistan and Iran to show “restraint”.
Iran had late on Monday launched ballistic missile strikes against targets in Iraq’s northern city of Irbil, prompting condemnation by the US.
The Iranian strikes come amid heightened tensions across the Middle East since the war in the Gaza Strip between Israel and the Iran-backed Palestinian group Hamas began on 7 October.
