Terrified onlookers were forced to flee when a cruise ship lost control while docking in Venice, smashing into a wharf and hitting a tourist boat.

Key points: The MSC Opera was captured ploughing into the dockside at the San Basilio Cruise Terminal

The MSC Opera was captured ploughing into the dockside at the San Basilio Cruise Terminal Two people were injured in the accident, according to Italian media

Two people were injured in the accident, according to Italian media The crash reportedly occurred after a cable used to link cruise ships to tug boats snapped

The crash happened about 8:30am Sunday (local time) on the Giudecca Canal, a major thoroughfare that leads to Saint Mark's Square.

In vision posted to social media, the vessel — identified by Italian media as the MSC Opera — is seen ploughing into the dockside at the San Basilio Cruise Terminal before hitting a smaller tourist boat.

Bystanders are seen running from the scene as the ship's horn blares behind them.

"Back, back, back, back," terminal staff yelled, as those nearby were ushered away from the incoming cruise ship.

Pino Musolino, chairman of the Northern Adriatic Sea Port Authority, said four people suffered minor injuries in the crash.

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The cruise ship's owner, MSC Cruises, said the ship was about to dock at a passenger terminal in Venice when it had a mechanical problem.

Two towboats guiding the cruise ship into Venice tried to stop the massive cruise ship, but they were unable to prevent it from ramming into the river boat.

"The two towboats tried to stop the giant and then a tow cable broke, cut by the collision with the river boat," Davide Calderan, president of a towboat association in Venice, told the Italian news agency ANSA.

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A view of the damaged harbour quay after the cruise ship collided with the tourist boat. ( AP: Vigili del Fuoco )

Mr Calderan said the cruise ship's engine was locked when the captain called for help.

Vigili del Fuoco, Italy's rescue service, said the situation was under control and divers were on scene.

Danilo Toninelli, Italy's Transport Minister, immediately called for cruise ships to be banned from using the Giudecca Canal in the wake of the incident.

"Today's accident in the port of Venice proves that cruise ships shouldn't be allowed to pass down the Giudecca anymore," he said.

"After many years of inertia, we are finally close to a solution to protect both the lagoon and tourism."

Cruise ships have earned the ire of Venetians in recent years, with hundreds of vessels sailing into the Venice lagoon during the six-month tourist season.

Last year the city hosted 594 cruise ships, and critics claim the currents created as the ships pass by are damaging the Renaissance buildings.

Cruise ships have earned the ire of Venetians in recent years. ( AP: Vigili del Fuoco )

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