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Israel remains on high alert for Iran's expected retaliation to the Israeli strike that killed several commanders at the Iranian embassy in Damascus.
The Israeli military is ready for "any scenario that may develop vis-à-vis Iran," said a statement from the Defence Minister Yoav Gallant after he held an "operational situation assessment" with senior military officers on Sunday.
Israel halted all leave for combat units and drafted reservists to boost its aerial defences last week, after Tehran promised to retaliate for the attack on April 1 that killed several Iranian generals including Mohammad Reza Zahedi, the commander of the Islamic Revolutionary Guard Corps' Quds Forces in Lebanon and Syria.
Israel has neither confirmed nor denied that it carried out the attack, which levelled the Iranian consulate in Damascus and killed 12 people in total, including seven IRGC members and a member of the Iran-backed Hezbollah militia.
The consular section resumed activities on Sunday after being closed for four days following the attack, Iran's Isna news agency reported.
Gen Mohammad Bagheri, Iran’s joint chief of staff, told mourners gathered for the funeral of Gen Zahedi on Friday that Iran will decide how and when to retaliate for the attack.
“The time, type, plan of the operation will be decided by us, in a way that makes Israel regret what it did," he said. "This will definitely be done.”
The Hezbollah General Secretary Hassan Nasrallah, who is based in Lebanon and aligned with Tehran, had described the attack as a "turning point" and pledged that the Iran-led "axis of resistance" would respond.
On Sunday, one of the senior advisers to Iran's Supreme Leader Ayatollah Ali Khamenei suggested retaliation could come against Israeli embassies.
“The embassies of the Zionist regime are no longer safe,” Yahya Rahim Safavi told Iran's Isna news agency.
Israel temporarily closed 28 of its embassies across the world over the weekend.
Isna also shared a graphic of nine missiles in the Iranian arsenal that it said could strike Israel.
On Thursday, residents across central Israel had reported that GPS services were being disrupted, an apparently deliberate measure to electronically jam guided missiles.
Iran has the option of retaliating against Israel using one of its proxy organisations across the region, including Hezbollah in Lebanon, a range of militias in Iraq and Syria, and the Houthis in Yemen.
The Houthis launched rockets and drone attacks at British, Israeli and US ships in the Red Sea on Sunday.
The Iran-aligned group said it had targeted a British ship and a number of US frigates in the Red Sea, while in the Arabian Sea and Indian Ocean it had attacked two Israeli vessels heading to Israeli ports. It said the attacks had taken place during the last 72 hours, without giving further details.
US Central Command said it had shot down one mobile surface-to air missile and an unmanned aerial vehicle launched by the Houthis. It said the attacks caused no injuries or damage.
Amid this threat of regional war, the Iranian Foreign Minister Hossein Amir-Abdollahian travelled to Oman on Sunday on the first leg of a tour across the Middle East.
"Amir-Abdollahian is travelling to Oman as the first destination of his regional tour at the head of a political and parliamentary delegation. Bilateral and regional issues such as Gaza will be discussed," the Iranian foreign ministry said.
Oman has traditionally played a neutral role in the region and often mediates between regional enemies.
Mr Amir-Abdollahian will then travel onwards to Syria on Monday, reported Iran's Tasnim agency.
Israel has repeatedly attacked Iranian targets in Syria since the outbreak of the Gaza war in October, and the subsequent cross-border clashes between Israeli forces and Hezbollah on Israel's northern border with Lebanon.
More than 33,000 Palestinians have been killed in six months of Israel's war in Gaza. Israel has come under mounting international pressure to halt its operations in Gaza this month, following the killing of foreign aid workers and with the death toll rising in the enclave.
The US has also repeatedly sought to avoid a regional escalation despite Israel's escalatory strikes on Iranian and allied targets.
