Two soldiers were killed in Israeli air strikes on military installations in Iran on Saturday, according to the Iranian army.
"The army of the Islamic Republic of Iran lost two of its fighters during the night when they faced projectiles from the criminal Zionist regime in defence of its territory," the army said in a statement carried by state television.
Israel struck military sites in Iran earlier on Saturday, saying it was retaliating against Tehran's strikes on Israel this month.
It was the latest attack in the escalating conflict between the heavily armed rivals.
The Israeli military later announced it had finished carrying out its strikes on Iran.
Iran is "entitled and obligated to defend itself against external aggressive acts", its foreign ministry said following the strikes.
Calling the Israeli attack a violation of international law, the ministry said in a statement that Tehran "recognises its responsibilities towards regional peace and security".
After the strikes, a Jordanian Armed Forces source told state media no military planes belonging to any conflicting regional parties were allowed to cross the country's airspace.
The semi-official Tasnim news agency reported Islamic Revolutionary Guard Corps bases that were attacked were not damaged and said Iran was resuming flights from 9am, local time, after a suspension during Israel's attack.
Neighbouring Iraq was also resuming flights, its state news agency said.
Lebanon, Iraq, Saudi Arabia, Qatar, Egypt, Bahrain, the United Arab Emirates and Pakistan all condemned Israel's strikes on Iran.
Saudi Arabia called it a "violation of its sovereignty" and international laws, while Pakistan's foreign ministry said Israel bore "full responsibility" for the war in the Middle East.
Syria's foreign ministry said it supported "Iran's legitimate right to defend itself and protect its territory and the lives of its citizens".
Iraq denounced "the international community's silence" on Israel's actions. The Iraqi state news agency reported no Iraqi military, economic or civilian facilities were affected during the strikes.
British Prime Minister Keir Starmer said Iran should not respond to the wave of Israeli strikes and urged restraint on all sides.
While Russia and the European Union echoed the call for mutual restraint, Germany's Chancellor Olaf Scholz called on Iran to de-escalate the conflict.
"My message to Iran is clear: We cannot continue with massive reactions of escalation," he said on X.
Hamas said it strongly condemned Israeli strikes on military targets in Iran.
"We … condemn in the strongest terms the Zionist aggression against the Islamic Republic of Iran, and the targeting of military sites in several provinces," the movement said in a statement.
The militant group called the move "a blatant violation of Iranian sovereignty and an escalation that threatens the security of the region".