Russia and Germany urge restraint as Iranian threat puts Middle East on edge

Russia and Germany on Thursday urged countries in the Middle East to show restraint and Israel said it was preparing to "meet all its security needs" in a region on edge over an Iranian threat to strike Israel.

The German airline Lufthansa, one of only two Western carriers flying to Tehran, extended a suspension of its flights to the Iranian capital and Russia warned against travel to the Middle East.

Iran has vowed revenge for the April 1 airstrike on its embassy compound in Damascus that killed a top Iranian general and six other Iranian military officers, ratcheting up tension in a region already strained by the Gaza war.

Read: Khamenei says Israel 'must be punished' for Syria embassy attack

Israel has not claimed responsibility for the attack, but Iranian Supreme Leader Ayatollah Ali Khamenei said on Wednesday Israel "must be punished and it shall be", saying it was tantamount to an attack on Iranian soil.

The "imperative for Iran to punish this rogue regime" might have been avoided had the U.N. Security Council condemned the strike and brought the perpetrators to justice, Tehran's mission to the United Nations said on Thursday.

Prime Minister Benjamin Netanyahu said Israel was keeping up its war in Gaza but making security preparations elsewhere.

"Whoever harms us, we will harm them. We are prepared to meet all of the security needs of the State of Israel, both defensively and offensively," he said in comments released following a visit to an air force base.

Read: Israel completed preparations for potential war with Iran, says defence minister

His comments come amid concern Iran is preparing to strike Israel in response for the killing of senior Iranian commanders in Damascus on April 1.

Conflict has spread across the Middle East since the eruption of the Gaza war, with Iran-backed groups declaring support for the Palestinians waging attacks from Lebanon, Yemen and Iraq. Tehran has avoided direct confrontation with Israel or the United States, while declaring support for its allies.

German Foreign Minister Annalena Baerbock called on her Iranian counterpart Hossein Amirabdollahian to urge "maximum restraint" to avoid further escalation.