Crown Prince Mohammed bin Salman’s crackdown on some of Saudi Arabia’s richest and most powerful men has put $33 billion of personal wealth at risk.

The stunning series of arrests has implicated three of the country’s richest people, including Prince Alwaleed bin Talal, who’s No. 50 on the Bloomberg Billionaires Index ranking of the world’s 500 richest people, with $19 billion. Also being held are the kingdom’s second- and fifth-wealthiest people, as well as a travel-agency mogul and Bakr Binladin, a scion of a one of the country’s biggest construction empires.

The arrests, which the crown prince said are part of a fight against corruption, reportedly have led the government to freeze the accounts of the more than three dozen men detained and believed to be held at the Riyadh Ritz-Carlton.

Alwaleed bin Talal, $19 billion

• Owns stakes in Twitter Inc., News Corp. and Citigroup Inc.
• Nephew of the late Saudi ruler, King Abdullah. Son of Prince Talal and Princess Mona El-Solh, daughter of Lebanon’s first prime minister, Riad El-Solh.
• Made his first billion dollars trading land and acting as a point man for multinational companies seeking local contracts.

Alwaleed’s publicly traded Kingdom Holding Group released a statement saying it “enjoys a solid financial position” and the government has “full confidence” in the company.

Mohammed Al Amoudi, $10.1 billion

• Controls an empire that has investments across Africa, Europe and Saudi Arabia.
• Born in Ethiopia to a Saudi father and Ethiopian mother.
• Moved to Saudi Arabia as a young man and made his first billion in the late 1980s through construction, aided by an early government contract to help build the country’s underground oil storage facility.
• Assets include Sweden’s largest oil refiner, Preem AB, real estate and numerous contracting businesses. In Ethiopia, where he’s said to be the biggest private investor, he owns hotels and a gold mine, and has invested hundreds of millions of dollars in large-scale farms growing coffee and rice.

Tim Pendry, Al Amoudi’s London-based spokesman said in a statement Monday that the arrest “is an internal matter for the kingdom and we have no further comment to make other than to say that the overseas businesses owned by the Sheikh remain unaffected by this development.”

Saleh Kamel, $3.7 billion

• Self-made finance and healthcare entrepreneur started running bus services for Hajj pilgrims and later founded the kingdom’s first driving school.
• Regarded as one of the pioneers of Islamic finance, a method of banking that complies with Islamic law and is today a $2.2 trillion industry.
• Kamel founded Manama, Bahrain-based Albaraka Banking Group, an Islamic bank with $23.4 billion in assets at the end of 2016.
• Carved out an early niche for himself by becoming the first non-government company to sell services to consumers.
• Jeddah-based holding group, Dallah Albaraka, owns more than a dozen businesses, spanning hospital operator Dallah Healthcare Company, real estate developments and snack-food factories.

Albaraka Banking Group said in a statement that the arrest didn’t have a direct impact on the company and that Kamel didn’t serve on the bank’s board.

Nasser Al Tayyar, $600 million

• The 60-year-old amassed a fortune that’s tied to publicly traded Al Tayyar Travel Group Holding Co., one of Saudi Arabia’s largest travel agencies.
• Founded the business in 1980 with four employees and about $300,000 after a stint in the reservations department of Saudi Arabian Airlines.
• The company books airfare and hotel rooms, and also organizes specialized travel, like foreign medical trips, and Hajj and Umrah pilgrimages to Islam’s holy cities.
• Al Tayyar’s shares slumped 10 percent at the close in Riyadh reaching their lowest since June 2012.

The company said in a statement to the Saudi Stock Exchange that its operations are continuing, and that it’s safeguarding the interests of its customers and shareholders.

Bakr Binladin

• The brother of Osama Bin Laden heads one of the kingdom’s largest construction companies, Saudi Binladin Group.
• The closely-held firm was started by Bakr’s father, Mohammed, in 1931, and has built some of the kingdom’s biggest and most notable projects, from the expansion of the Grand Mosque in Mecca, to airports and King Abdullah Economic City.
• The company had revenue of $3 billion in 2016, and ownership is split among more than 20 descendants, according to Orbis, a database of company information published by Bureau van Dijk.

Phone calls made to the company headquarters after hours went unanswered.

Two of the four Saudis on the Bloomberg index haven’t been detained in the sweep: hotel magnate Mohamed bin Issa Al Jaber, who has an $8.3 billion fortune and splits his time between Paris, London, Vienna and Jeddah, and Prince Sultan Bin Mohammed Al Kabeer, the biggest individual shareholder in food processor Almarai Company, who has $4.7 billion.