Yemen's Iran-backed Houthi rebels said early Thursday they had attacked two Saudi oil tankers in the Red Sea, and the U.S. military conducted a 12th night of strikes against Iran as the two countries vie for control of vital shipping lanes.

The Houthi attack in the Red Sea threatened to open a new front in a war that has roiled the global economy, sending prices for fuel and other goods surging across the world. With the standoff in the Gulf deepening, there were no signs of progress in diplomatic efforts to end the conflict.

Iran again denied the existence of any secret nuclear complex at Kolang mountain on Wednesday, after U.S. President Donald Trump threatened to strike the site in the center of the country.

Gaza's civil defense agency and witnesses said Israeli strikes killed 12 people, including a family of six, in the Palestinian territory on Tuesday.

Dubai will offer more than $800 worth of discounts and deals to residents who bring friends and family to visit, the emirate's media office said on Wednesday, as months of war have battered its tourism sector.

The Jordanian army said it intercepted four Iranian missiles on Wednesday, adding that two others fell in an open area, as Tehran pressed its attacks across the region.

Top officials and ministers in the United Arab Emirates and Saudi Arabia have recently posted about friendship and unity on social media, signaling a rapprochement months after a public fall-out between the two largest Arab economies.

The United States plans to announce an agreement with Saudi Arabia on Wednesday that would give the country a civilian nuclear program, according to media reports, amid renewed fighting between the Gulf oil giant and Iran-backed Houthi rebels in Yemen.

Iran and U.S. forces traded new military attacks, with Tehran warning of "more decisive and powerful" strikes ahead as the conflict threatened to widen with a blockade of Saudi ports by Houthi rebels in Yemen.

Fresh U.S. strikes triggered air defenses in Tehran on Wednesday after President Donald Trump warned he was "not finished" with a war with Iran that has already cost his nation $37.5 billion.

After the foes' fighting over the strategic Strait of Hormuz led to the collapse of a preliminary deal, the Middle East war has expanded to include the region's other key chokepoint for global oil supplies.

Kuwait said Tuesday that Iran had again attacked power and desalination plants critical to the tiny desert nation.

The statement from Kuwait’s Electricity, Water and Renewable Energy Ministry said that Tehran had struck the plants for a fourth day in a row on Monday night.