Rome, Italy (CNN) A cruise ship crashed into a Venice dock on Sunday, hitting a moored tourist boat and sending onlookers running for safety in what one witness said resembled a "scene from a disaster movie."

The cruise ship, MSC Opera, rammed into the San Basilio terminal, and hit a smaller tourist boat -- the River Countess -- that was docked there, the local port authority told CNN.

Four people suffered "light injuries" in the accident, it said.

#Venezia #VIDEO la nave da crociera #Opera di @MSC_Crociere fuori controllo ha speronato stamattina il battello fluviale #Michelangelo e la banchina.



Qualcuno ci spiegherà perché le navi che salvano vite sono sotto sequestro, mentre queste #grandinavi sono libere di far danni. pic.twitter.com/mSyhCMvvZc — Beppe Caccia (@beppecaccia) June 2, 2019

The incident happened at around 8.30am local time on the Giudecca canal, one of the busiest in the Italian city which is hugely popular with tourists.

Video on Twitter showed the huge cruise ship heading for the dock, shoving the smaller boat out of the way, and causing onlookers on land to flee.

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