Why have Israel and Iran attacked each other?
An Israeli missile has hit Iran, US officials have told the BBC's partner CBS News - an attack that is widely seen as its response to Iran's missile and drone attack on Israel.
Iran's own direct attack on Israel - its first ever - was in turn retaliation for an Israeli strike on the Iranian consulate in the Syrian capital Damascus, which killed senior military commanders.
Why are Israel and Iran enemies?
Previously Israel and Iran had been engaged in a years-long shadow war - attacking each other's assets without admitting responsibility.
Those attacks have ratcheted up considerably during the current war in Gaza sparked by the Palestinian group Hamas's assault on nearby Israeli communities last October.
The two countries were allies until the 1979 Islamic revolution in Iran, which brought in a regime that has used opposing Israel as a key part of its ideology.
Iran does not recognise Israel's right to exist and seeks its eradication. The country's supreme leader, Ayatollah Ali Khamenei, has previously called Israel a "cancerous tumour" that "will undoubtedly be uprooted and destroyed".
Israel believes that Iran poses an existential threat as evidenced by Tehran's rhetoric, its build-up of proxy forces in the region including the Lebanese Shia militant group Hezbollah that are sworn to Israel's destruction, and its funding and arming of Palestinian groups including Hamas.
It also accuses Iran of secretly trying to develop nuclear weapons, though Iran denies seeking to build a nuclear bomb.
Why did Israel attack Iran's consulate in Syria?
The 1 April air strike on an Iranian consulate building in the Syrian capital Damascus killed 13 people. Iran said it was a violation of its sovereignty.
Those killed included Brig Gen Mohammad Reza Zahedi - a senior commander in the Quds force, the overseas branch of Iran's elite Republican Guards (IRGC). He had been a key figure in the Iranian operation to arm the Lebanese Shia armed group Hezbollah.
The consulate attack follows a pattern of air strikes against Iranian targets widely attributed to Israel. Several senior IRGC commanders have been killed in air strikes in Syria in recent months.
The IRGC channels arms and equipment, including high precision missiles, through Syria to Hezbollah. Israel is trying to stop these deliveries, as well as seeking to prevent Iran from strengthening its military presence in Syria.
Source: BBC