Story highlights Donald and Melania Trump traveled to Hamburg Thursday ahead of the G20 summit

Activists have planned days of demonstrations to protest the G20 summit

Washington (CNN) First lady Melania Trump is unable to leave her Hamburg hotel and attend events with other G20 spouses because of protests, her spokeswoman said Friday.

"Hamburg police couldn't provide clearance for us to leave," Stephanie Grisham told reporters in Hamburg.

The spouses of G20 leaders are scheduled to tour a climate change center in Hamburg and take a river cruise while the world leaders attend the summit, according to media reports.

Donald and Melania Trump traveled to Hamburg Thursday ahead of the G20 summit, which kicked off Friday morning. Trump is scheduled to meet with Russian President Vladimir Putin and other world leaders during the day.

Activists have planned days of demonstrations to protest the G20 summit. Protesters in the anti-capitalist Welcome to Hell march clashed with police Thursday afternoon and into the night. Police used water cannons on the crowd and protesters threw bottles and smoke bombs.

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