Iran condemned strikes on Yemen by US and British forces on Friday, saying that the attacks against Tehran-backed Huthi rebels were "arbitrary" and a "violation" of international law.
The overnight strikes followed weeks of missile and drone attacks by the Huthis against Red Sea shipping which they say have been in solidarity with Palestinians in the war-ravaged Gaza Strip.
Foreign ministry spokesman Nasser Kanani said Iran "strongly condemns the military attacks of the United States and the United Kingdom this morning on several Yemeni cities".
He said the strikes were "an arbitrary action, a clear violation of the sovereignty and territorial integrity of Yemen, and a violation of international laws and regulations".
The United States, Britain and their allies said in a joint statement after the air strikes that their goal "remains to de-escalate tensions and restore stability in the Red Sea".
The attacks by the Huthis have disrupted traffic along the vital trade route, with many firms rerouting their vessels around the tip of Africa, with knock-on effects for the world economy.
Kanani warned that the attacks "will have no result other than fuelling insecurity and instability in the region", as well as "diverting the world's attention from the crimes" in Gaza, where Israel has been fighting the Palestinian territory's Hamas rulers.
The spokesman urged the international community to take action "to prevent the spread of war".
Foreign Minister Hossein Amir-Abdollahian voiced support for the Huthis' campaign in support of the Palestinians.
"Yemen's action in supporting the women and children of Gaza and confronting the Israeli regime's genocide is commendable," he said on X, formerly Twitter.
Hundreds rallied after Friday prayers in Tehran in support of the people of Gaza and Yemen, chanting slogans against the United States, Britain and Israel, an AFP journalist reported.
State television aired footage of similar rallies in other Iranian cities, and later broadcast images from a protest outside the British embassy in Tehran with people waving the Palestinian and Yemeni flags.
Protesters chanted "Down with Israel", "Down with the US" and "Down with Britain" as they burnt the three countries' flags, an AFP journalist said.
The Israel-Hamas war erupted with attacks by Palestinian militants on southern Israel on October 7, that resulted in about 1,140 deaths, mostly civilians, according to an AFP tally based on Israeli figures.
Iran, which supports Hamas financially and militarily, has hailed the attack but denied any involvement.
Israel has responded with a relentless military campaign that has killed more than 23,700 people in Gaza, the majority of them women and children, according to the health ministry in the Hamas-ruled territory.
Yemen's Huthi rebels -- part of a Tehran-aligned "axis of resistance" against Israel and its allies -- seized the capital Sanaa in 2014 and still control large swathes of the country despite a protracted Saudi-led military intervention.
Washington had said Iran was "deeply involved" in the Huthis' maritime attacks, a claim Tehran has denied.
President Ebrahim Raisi has said Iran sees it as "its duty to support the resistance groups", but insisted that they "are independent in their opinion, decision and action".
