The Cyprus-flagged vessel, measuring more than 100 metres (330 feet) long, was harboured at the port of Marina di Carrara near Massa "when the force of the waves caused the anchor to shift and the vessel to drift dangerously towards the coast", the coastguard said in a statement.

Pushed by strong winds and the current, the ship struck a pier to the south at Massa.

Rescuers intervened to pull the ship's 12-member crew, mostly Ukrainians, to safety, it said.

The mayor of Massa, Francesco Persiani, told local media he was concerned about the possibility of spilled fuel, though there had not yet been any indication of a leak.

He said the ship contained 102 tons of diesel, calling it "potentially a small ecological bomb".

"Obviously the weather conditions in the ocean don't allow us to understand exactly in what condition the ship is in, whether there has been a steady spilling of diesel," he said in a video posted on Facebook.