A wave of Houthi attacks Tuesday on Saudi Arabia wounded more than 70 people and ignited fires at several oil facilities and utilities in the kingdom's southern region, authorities said, a major escalation in the renewed conflict between an important U.S. ally and the Iranian-backed rebels in Yemen.

The attacks come after weeks of escalating clashes between the Houthis and Saudi-backed government forces in Yemen, which shattered a four-year truce in the country's civil war.

Iran's foreign ministry on Monday warned South Korea against military deployment or involvement in U.S. operations in the Strait of Hormuz, saying such a move would have "serious consequences".

Yemen's Houthis on Monday accused Saudi Arabia of carrying out airstrikes on various areas of Yemen as the rebels push on with an offensive to seize territory bordering the strategic Bab al-Mandeb strait.

Iran's top negotiator on Sunday threatened a more forceful response to any further U.S. attacks after Tehran targeted American warships in their latest round of clashes.

Iran said Sunday that its forces attacked a U.S. naval drone trying to enter the Strait of Hormuz, hours after targeting ships in retaliation for American strikes on three oil tankers.

Iranian authorities have arrested a number of people accused of appearing in a rare video waving the flag of an outlawed opposition group, state television said Sunday.

President Donald Trump said that the Iran war was "small potatoes" for the United States, in his administration's latest bid to play down the conflict ahead of crucial midterm elections.

Iranian media on Saturday reported several explosions near the country's major oil hub of Kharg Island in the Gulf, days after renewed fighting broke out with the United States.

Hamas called on Arab and Muslim countries on Friday to oppose a proposal from two Israeli ministers to remove Palestinians from the Gaza Strip and send them abroad.

"Escalating statements by ministers in the Israeli government regarding the continued adoption of plans to displace the Palestinian people from the Gaza Strip represent an extremely dangerous development," Hamas spokesman Hazem Qassem said in a statement.

The Sultan of Oman will visit Britain for a three-day state visit next month as the Arab nation that controls the southern shore of the Strait of Hormuz comes under pressure from both the U.S. and Iran.

King Charles III and Queen Camilla will host Sultan Haitham bin Tarik at Windsor Castle from Oct. 20 to Oct. 22, Buckingham Palace said in a statement Thursday. Details of the visit were not released.