The United Nations and Red Cross on Tuesday urged the Saudi-led coalition fighting in Yemen to re-open an aid lifeline to bring imported food and medicine into the country.

All major Gulf stock markets slid on Tuesday on jitters about Saudi Arabia’s sweeping anti-graft purge, a campaign seen by critics as a populist power grab but by ordinary Saudis as an overdue attack on the sleaze of a moneyed ultra-elite.

Saudi Arabia has opened a new front in its regional proxy war with Iran, threatening Tehran’s powerful ally Hezbollah and its home country Lebanon to try to regain the upper hand.

Saudi Arabia’s crown prince directed ministers on Tuesday to ensure that national and multinational companies, including those wholly or partly owned by individuals under investigation in sweeping anti-corruption probe, were not disrupted.

The United States accused Iran on Tuesday of supplying Yemen’s Houthi rebels with a missile that was fired into Saudi Arabia in July and called for the United Nations to hold Tehran accountable for violating two U.N. Security Council resolutions.

Prominent Bahraini opposition figure Ali Al-Aswad said the Bahraini government’s official position on recent events in Saudi Arabia was “siding with party that has the upper hand.”

Saudi Arabia’s Attorney General said on Monday detailed questioning of individuals detained on the back of an anti-corruption probe had taken place and “a great deal of evidence” had already been gathered.

Iranian Foreign Minister Mohammad Javad Zarif said on Monday Saudi Arabia was blaming Iran for the consequences of its own “wars of aggression”, after his Saudi counterpart accused Tehran of threatening regional security.

U.S. President Donald Trump on Monday endorsed a move by Saudi Arabia’s future king that tightened his grip on power through the arrests of royals, ministers and investors in an anti-corruption purge.

The Saudi-led military coalition fighting against the Houthi movement in Yemen said on Monday it would close all air, land and sea ports to the Arabian Peninsula country to stem the flow of arms to the Houthis from Iran.

Saudi Arabia’s crown prince said Iran’s supply of rockets to militias in Yemen is an act of “direct military aggression” that could be an act of war, state media reported on Tuesday.

Saudi Arabia accused Lebanon on Monday of declaring war against it because of aggression by the Iran-backed Lebanese Shi‘ite group Hezbollah, a dramatic escalation of a crisis threatening to destabilize the tiny Arab country.

Saudi Arabian banks have begun freezing the accounts of suspects ensnared in an anti-corruption probe, banking and business sources told Reuters on Monday.

Lebanon’s Shi‘ite Hezbollah group on Sunday accused Saudi Arabia of forcing Lebanese Prime Minister Saad al-Hariri to quit, and called for calm in an effort to contain the political crisis unleashed by his resignation.

The deputy governor of Saudi Arabia’s southern Asir province and several colleagues were killed in a helicopter crash on Sunday, Saudi state TV Ekhbariya reported.

Bribery, embezzlement, money laundering and abuse of power are among the accusations levelled against dozens of Saudi princes, officials and businessmen detained in an anti-corruption probe, a Saudi official told Reuters on Monday.

The head of Iran's Revolutionary Guards denied on Sunday accusations by Donald Trump that Iran was behind the firing of a ballistic missile at Saudi Arabia from warring Yemen, rejecting it as one of the U.S. president's "slanders".

A Saudi-led coalition accused Yemen's Houthi militia of a "dangerous escalation" on Sunday after Saudi air defense forces intercepted a ballistic missile fired towards Riyadh.

Saudi Arabia’s air defense forces intercepted a ballistic missile fired from warring Yemen over the capital Riyadh on Saturday, state news agencies reported.

Saudi Arabia has arrested dozens of senior figures including princes, ministers and a top business tycoon, with authorities on Sunday pledging "fair" justice after a sweeping purge seen as consolidating the crown prince's hold on power.