Saudi Arabia's attorney general said "no one is above the law" after the princes were detained outside a palace in Riyadh, where they had gathered last week to demonstrate against a government decision to stop paying the water and electricity bills of royals.
They also demanded compensation for a death sentence issued against one of their cousins, convicted of murder and executed in 2016, attorney general Saud al-Mojeb said.
"A group of 11 princes staged a sit-in at the historic Qasr Al-Hokm palace on Thursday... objecting a recent royal order that halted payments by the state to members of the royal family to cover their electricity and water utility bills," the attorney general said.
"Despite being informed that their demands are not lawful, the 11 princes refused to leave the area, disrupting public peace and order".
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The names of the 11 princes have not been made public.
Prince Mohammed, who sidelined his cousin as heir to the throne, has since consolidated his grip on the kingdom's economy in a meteoric rise in the royal court.
The recent arrests come amid a string of government spending cuts as Saudi Arabia, the world's largest producer of oil, pushes to diversify its economy following the 2014 drop in global oil prices.
The country plans to slash its generous welfare programme and open energy giant Saudi Aramco to partial privatisation.
The economic overhaul has been linked to the arrest of more than 200 princes in an anti-corruption purge in November spearheaded by Prince Mohammed.
Most of those detained were held at the palatial Ritz- Carlton hotel in Riyadh, which has turned into a luxury prison. Some have since reached settlements with the government.
On January 1, Saudi Arabia also hiked gasoline and fuel prices and imposed a five percent value-added tax on most goods and services, ending its decades-long tax-free policy.
The Gulf kingdom has also intensified efforts to boost employment of its own citizens. Most working Saudis are employed by the state.
King Salman yesterday announced a string of benefits for Saudi citizens, particularly students, military personnel and public servants, to "soften the impact of the economic reforms" in the coming year.
Saudi Arabia's information minister on Sunday said the handouts would cost the government up to 80 billion riyals (USD 13.3 billion, 11 billion euros) in 2018.
The unemployment rate among Saudis aged 15 to 24 stood at 32.6 per cent last year, according to the International Labour Organisation.