Several visitors to California’s Great America in Santa Clara were assaulted by groups of roving thieves at the amusement park’s Halloween Haunt event over the weekend, according to witnesses and local authorities.

Santa Clara police said they responded Saturday evening to large groups of people harassing guests.

Visitors reported several youths confronting them in the park’s Halloween exhibits, taking their wallets and phones. One visitor reported a robber armed with a Taser. The mayhem sent guests fleeing for the exits.

“Got punched in the face, evacuated out from mazes and it was just all bad,” wrote one visitor on Twitter.

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The park did not immediately return phone calls Monday seeking details of what happened.

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander