Saudi Arabia’s top military commander in its years-long war in Yemen and his prince son have been removed from their posts along with other officials as part of an anti-corruption investigation.

The announcement, early on Tuesday, attributed the actions to a referral by Saudi Arabia’s crown prince, Mohammed bin Salman. The 35-year-old son of King Salman has previously carried out mass arrests in a similar anti-corruption drive that also targeted potential rivals to his rule.

A statement on the state-run Saudi Press Agency referred to “suspicious financial dealings monitored at the Ministry of Defence”, without elaborating.

As a result, the statement said the kingdom fired Lt Gen Fahad bin Turki bin Abdulaziz, a prince in Saudi Arabia’s large ruling family in charge of allied forces in Yemen fighting the Iranian-allied Houthi rebels.

Authorities also removed his son, Prince Abdulaziz bin Fahad bin Turki, from his position as the deputy governor of Saudi Arabia’s al-Jouf region in the kingdom’s north-west.

Four other officials are also being investigated on the orders of 84-year-old King Salman, the statement said. It was not immediately clear if those accused had been detained or if they had lawyers.

Anti-corruption officials “shall complete the investigation procedures with all relevant military and civil officials, take the necessary legal measures against them and submit the outcomes,” the statement said.

Lt Gen Fahad took over leading the Yemen war in February 2018 following years of stalemate. The Houthis still hold the capital, Sana’a. He previously served as a paratrooper and special forces commander, and also oversaw the Royal Saudi Land Forces.

He took over the coalition as part of a mass restructuring of the Saudi military at the time.

The war in Yemen – which has killed over 100,000 people, displaced millions and shattered the Arab world’s poorest country – has become the world’s worst humanitarian crisis. It began with Houthi rebels seizing Sana’a in September 2014, then marching south. Saudi Arabia and its allies entered the conflict in March 2015, led by Bin Salman as the Saudi defence minister.

The war has become a regional conflict, as the Iranian-backed Houthis hold the north and a variety of forces operate in the south under the umbrella of the Saudi-led coalition.

There has been international condemnation of Saudi airstrikes that have killed civilians and the torture of prisoners at Emirati-controlled prisons. The Houthis face outrage over stolen humanitarian aid, indiscriminately using landmines and sending child soldiers into the conflict.

The Saudi-led coalition has splintered as the war has dragged on, especially after Emirati troops withdrew last year. Separatists backed by the United Arab Emirates have openly fought against Yemen’s internationally recognised government, which has been based in Saudi Arabia for years. That violence has flared again in recent days.

After coming to power, Bin Salman has been behind several anti-corruption campaigns, including turning Riyadh’s Ritz-Carlton hotel into a luxury prison in late 2017 as part of a mass arrest of businessmen, royals and others. Those released agreed to sign over some of their assets, giving the crackdown the feel of a shakedown.