Melania Trump is among a host of A-listers allegedly trapped in a Hamburg hotel room because of riots during the G20 meeting in Germany.
World leaders were apparently diverted before they could attend the meeting, including husband Donald Trump.
The rioting in the German port city became so bad that police urgently called for reinforcements.
Footage showed the city looking like a war zone because of the trouble.
A spokeswoman for the US First Lady told press agencies that because of the rioting, Melania was among a number of spouses unable to leave the safety of a hotel.
Others affected included Theresa May’s husband Philip and French president Emmanuel Macron’s wife Brigitte.
They were also meant to visit a climate change centre, but that was cancelled.
Up to 100,000 anti-capitalist protesters were expected to descend on the city today, as heads of state including US President Donald Trump and Russian leader Vladimir Putin meet for the G20 talks.
It was the first meeting as leaders between Trump and Putin
The trouble started yesterday.
Police said that more than 100 officers were hurt during clashes, one of who suffered an eye injury.
There were some 30 arrests.
Police, who were bolstered by the presence of officers from Austria requested further back-up because of the extent of the trouble.