Ballistic missiles fired by Yemen's Houthi rebels struck three commercial ships Sunday in the Red Sea, while a U.S. warship shot down three drones in self-defense during the hourslong assault, the U.S. military said. The Iranian-backed Houthis claimed two of the attacks.

The strikes marked an escalation in a series of maritime attacks in the Mideast linked to the Israel-Hamas war, as multiple vessels found themselves in the crosshairs of a single Houthi assault for the first time in the conflict. The U.S. vowed to "consider all appropriate responses" in the wake of the attack, specifically calling out Iran, after tensions have been high for years now over Tehran's rapidly advancing nuclear program.

The Israeli military on Monday renewed its calls for mass evacuations from the southern town of Khan Younis, where tens of thousands of displaced Palestinians have sought refuge in recent weeks, as it widened its ground offensive and bombarded targets across the Gaza Strip.

The expanded offensive, following the collapse of a weeklong cease-fire, is aimed at eliminating Gaza's Hamas rulers, whose Oct. 7 attack into Israel triggered the deadliest Israeli-Palestinian violence in decades. The war has already killed thousands of Palestinians and displaced over three-fourths of the territory's population of 2.3 million Palestinians, who are running out of safe places to go.

A "self-defense strike" was carried out in northern Iraq against a drone launch site, a U.S. military official said, after an air strike killed five pro-Iranian militants there.

"A self-defense strike was carried out on a drone staging site," the official said on condition of anonymity. It took place "in the vicinity of Kirkuk" and targeted "an imminent threat", he added.

U.S. Defense Secretary Lloyd Austin on Saturday urged Israel to protect civilians as it battles Hamas in Gaza, saying that shielding noncombatants is necessary for victory in the urban fight against the Palestinian militant group.

Fighting between Israel and Hamas resumed the day before after a week-long truce between the two sides collapsed, with both sides blaming the other for the breakdown of the deal and the resumption of violence.

Iran's paramilitary Revolutionary Guard stated through its website that two of its forces stationed in Syria were killed in an Israeli airstrike Saturday.

The report on the Guard's news portal identified the two members as Mohammad Ali Ataei Shourcheh and Panah Taghizadeh, and said they were carrying out an advisory mission in Syria. It did not elaborate on their rank, or the area where they were killed.

Vice President Kamala Harris engaged in a speed round of diplomatic talks with Arab leaders on Saturday where she focused on shaping the outlook for a post-conflict Gaza while calling on Israel to do more to protect Palestinian civilians from the "devastating" bombardment.

She made a hastily planned trip to the United Arab Emirates as the top American representative at the U.N. climate conference but the Israel-Ham1,as war was a main objective of her visit. She met with leaders of the United Arab Emirates, Egypt and Jordan and spoke by phone with Qatar's emir.

Israel's military on Sunday ordered more areas in and around Gaza's second-largest city of Khan Younis to evacuate, as it shifted its offensive to the southern half of the territory where it says many Hamas leaders are hiding.

Heavy bombardments were reported overnight and into Sunday in the area of Khan Younis and the southern city of Rafah, as well as parts of the north that had been the focus of Israel's blistering air and ground campaign.

Israeli air strikes killed two Syrian pro-Hezbollah fighters when they hit sites belonging to the Iran-backed group near Damascus early on Saturday, a war monitor told AFP.

The strikes near Damascus came less than 24 hours after the end of a Gaza truce between Hezbollah ally Hamas and Israel.

Israel carried out deadly bombardments in Gaza for a second day on Saturday, hitting hundreds of targets, after a week-long truce with Hamas militants collapsed despite international calls for an extension.

As world leaders gathered for the COP28 climate summit in Dubai, the collapse of a cease-fire in the Israel-Hamas war Friday plunged the conflict back into open combat and cast a long shadow over the talks.

Israel's top diplomat for the Middle East huddled with leaders at the summit as his colleagues went through a book of posters of those held hostage by the militant group Hamas, placing yellow "released" stickers by some while looking at others still held. Meanwhile, just a street away at the Palestinian territories' first-ever pavilion, an official gave a horrified look when Associated Press journalists gave her the news that Israeli airstrikes and ground fighting in the Gaza Strip had resumed.