The recently deposed crown prince of Saudi Arabia, Mohammed bin Nayef, has been barred from leaving the kingdom and confined to his palace in the coastal city of Jidda, according to four current and former American officials and Saudis close to the royal family. The new restrictions on the man who until last week was next in line to the throne and ran the kingdom’s powerful internal security services sought to limit any potential opposition for the new crown prince, Mohammed bin Salman, 31, the officials said, speaking on the condition of anonymity so as not to jeopardize relationships with Saudi royals. It was unclear how long the restrictions would remain in place. An adviser to the Saudi royal court referred queries to the Information Ministry, whose officials could not immediately be reached for comment on Wednesday. A senior official in the Saudi Foreign Ministry reached by telephone on Wednesday night described the account as “baseless and false.” The Saudi monarch, King Salman, shook up the line of succession last week with a string of royal decrees that promoted his favorite son, Mohammed bin Salman, to crown prince and removed Mohammed bin Nayef, 57, from the line of succession.