RIYADH, Saudi Arabia (AP) — Saudi Arabia has arrested dozens of princes and former officials, including a well-known billionaire with extensive holdings in Western companies, as part of a sweeping anti-corruption probe that further cements control in the hands of its young crown prince.

A high-level employee at Prince Alwaleed bin Talal's Kingdom Holding Co. told The Associated Press that the royal was among those detained overnight Saturday. The employee, who spoke on condition of anonymity due to fear of repercussions, said he received calls from several security bodies notifying him of the arrest.

The surprise arrests, which also reportedly include two of the late King Abdullah's sons, were being hailed by pro-government media outlets as the greatest sign yet that Crown Prince Mohammed bin Salman is serious about reforming the country, which has long been plagued by allegations of corruption at the highest levels of government. The moves come barely two weeks after Saudi Arabia hosted a major investment conference.

Analysts suggested the corruption probe, which targeted key members of the royal family, was a show of force by the crown prince, aimed at undermining any potential rivals.

A Saudi government official with close ties to security says 11 princes and 38 former government ministers, deputies and businessmen are being held in five-star hotels across the capital, Riyadh. The official spoke to The Associated Press on condition of anonymity because he was not authorized to speak to the press.

The scale of the arrests is unprecedented in Saudi Arabia, where senior royals and their business associates have long been viewed as untouchable and seemingly operate above the law. Saudi nationals have long complained of rampant corruption in government and of public funds being squandered or misused by people in power.

It is not clear what Prince Alwaleed or others are being investigated for.

The prince is one of the Middle East's richest people. His many investments include Twitter, Apple, Rupert Murdoch's News Corp., Citigroup, and the Four Seasons, Fairmont and Movenpick hotel chains. He is also an investor in ride-sharing services Lyft and Careem, both competitors to Uber in the U.S. and the Middle East, respectively.

The prince, often pictured on his 85.65-meter (281 foot) superyacht in the Mediterranean, is among the most outspoken Saudi royals and a longtime advocate for women's rights. He is also majority owner of the popular Rotana Group of Arabic channels.

The Associated Press reached out overnight to Kingdom Holding for comment. There was no response as of Sunday morning.

The Finance Ministry said in a statement the anti-corruption probe "opens a new era of transparency and accountability," enhances confidence in the rule of law and improves the kingdom's investment climate.

The kingdom's top council of clerics issued a statement saying it is an Islamic duty to fight corruption— essentially giving religious backing to the high-level arrests being reported. And a top royal court official, Badr al-Asaker, on Sunday appeared to confirm the arrests on Twitter, describing a "historic and black night against the corrupt."

News of the arrests broke within hours of King Salman announcing the formation of a new anti-corruption committee headed by his son, the 32-year-old crown prince.

The king also ousted Prince Miteb bin Abdullah from his post as head of the National Guard overnight. The prince is reportedly among those detained in the sweep, as is his brother, Prince Turki bin Abdullah, who was once governor of Riyadh. Both are sons of the late King Abdullah, who ruled before his half brother King Salman.

Saudi Twitter accounts released several other names of those arrested, such as: Alwalid al-Ibrahim, a powerful Saudi businessman with ties to the royal family who runs the Arabic satellite group MBC; Amr al-Dabbagh, the former head of the Saudi Arabian General Investment Authority; Ibrahim Assaf, the former finance minister; and Bakr Binladin, head of the Saudi Binladin Group, a major business conglomerate.

Reports suggested those detained were being held in the Ritz Carlton in Riyadh, which only days earlier hosted the major investment conference. The phone number for the hotel had been disconnected by Sunday morning and a Dubai-based spokeswoman for the hotel chain did not respond to a request for comment.

The government said the anti-corruption committee has the right to issue arrest warrants, impose travel restrictions and freeze bank accounts. It can also trace funds, prevent the transfer of funds or the liquidation of assets, and take other precautionary measures until cases are referred to the judiciary.

Kristian Coates Ulrichsen, a research fellow at the James A. Baker III Institute for Public Policy at Rice University, said the arrests are designed to further smooth the crown prince's eventual succession to the throne.

"As a leader who is set to remain in power for decades, Mohammed bin Salman is remaking the kingdom in his own image and signaling a potentially significant move away from the consensual balancing of competing interests that characterized Saudi rule in the past," Ulrichsen said.

Prince Miteb was replaced by a lesser known royal, Prince Khalid bin Ayyaf al-Muqrin, to head the National Guard— a prestigious force tasked with protecting the royal family, as well as important holy sites in Mecca and Medina, and oil and gas sites.

Prince Miteb was once considered a contender for the throne. Just three months ago, Prince Mohammed bin Nayef was plucked from the line of succession and from his post as interior minister, overseeing internal security.

The arrests came as Lebanon's prime minister, a close Saudi ally, announced his own resignation from the Saudi capital.

Saudi Arabia then said its forces intercepted a ballistic missile fired by Iran-backed rebels in Yemen toward one of the kingdom's major international airports on the outskirts of Riyadh. A Saudi-led coalition launched a war against the Houthi rebels and their allies in March 2015 that grinds on today. A wave of airstrikes hit the rebel-held capital, Sanaa, overnight, apparently launched in response to the missile.

The missile fire drew an immediate rebuke from President Donald Trump.

"A shot was just taken by Iran, in my opinion, at Saudi Arabia. And our system knocked it down," Trump said, referring to the Patriot missile batteries Saudi Arabia has purchased from the U.S.

Trump's son-in-law and White House adviser Jared Kushner and others made an unannounced trip recently to Riyadh. Trump earlier Saturday said he spoke to King Salman about listing the kingdom's massive state-run oil company, Saudi Aramco, in the United States.

___

Batrawy reported from Dubai, United Arab Emirates. Associated Press writers Jon Gambrell and Fay Abuelgasim in Dubai and Jonathan Lemire aboard Air Force One contributed to this report.