Iran launched a swarm of explosive drones and fired missiles at Israel late on Saturday (Apr 13) in its first ever direct attack on Israeli territory, risking a major escalation as the United States pledged "ironclad" backing for Israel.

Sirens wailed and Reuters journalists in Israel said they heard distant heavy thuds and bangs from what local media called aerial interceptions of explosive drones. Authorities said a 7-year-old girl was critically injured.

Israel's military spokesperson Rear Admiral Daniel Hagari said Iran launched dozens of ground-to-ground missiles at Israel, most of which were intercepted outside Israeli borders. They included more than 10 cruise missiles, he said.

The Iranian salvo amounted to more than 200 drones and missiles so far, Hagari said, and had caused light damage to one Israeli military facility.

The Israeli military said later that it was not advising any residents to prepare to take shelter, revising an earlier alert in what appeared to signal the end of the threat.

Israel's Channel 12 TV cited an unnamed Israeli official as saying there would be a "significant response" to the attack.

Iran has vowed retaliation for what it called an Israeli strike on its Damascus consulate in April. The strike killed seven Revolutionary Guards officers including two senior commanders.

Israel has neither confirmed nor denied responsibility for the consulate attack.

"Should the Israeli regime make another mistake, Iran's response will be considerably more severe," the Iranian mission to the United Nations said. However, it also said Iran now "deemed the matter concluded".

United Nations Secretary-General Antonio Guterres condemned Iran's attack, and said he was "deeply alarmed about the very real danger of a devastating region-wide escalation".

US President Joe Biden, who on Friday had warned Iran against an attack, cut short a visit to his home state of Delaware to meet national security advisers in the White House Situation Room. He pledged to stand with Israel.

"Our commitment to Israel’s security against threats from Iran and its proxies is ironclad," he said on X after the meeting.

On Sunday, China expressed its concern over what was Iran's first direct attack on Israeli territory. It raised the threat of a wider conflict in a region where China has sought to play a role as a mediator and from where it sources a growing proportion of its energy imports.

"China expresses deep concern over the current escalation and calls on relevant parties to exercise calm and restraint to prevent further escalations," said a Chinese foreign ministry spokesman.

"China calls on the international community, especially countries with influence, to play a constructive role for the peace and stability of the region," the spokesman added.