At least three people were killed and six injured when a container ship rammed a control tower in the northern Italian port city of Genoa late on Tuesday, harbour officials quoted on local television said.
"It is a terrible tragedy," the head of the Genoa Port Authority Luigi Merlo told local Genoa television station Primocanale. "At the moment there is no explanation for the accident."
Two of the dead were harbour officials and the third was one of the pilots, local Primocanale quoted officials as saying.
As well as those confirmed dead or injured, as many as 10 more people were still missing after the accident, which destroyed one of the harbour's main control towers.
The incident occurred in calm conditions as the ship, owned by a local fleet operator, was manoeuvring out of the port with the assistance of tugboats, under the control of two pilots.
Television pictures showed rescue services searching the water near the tower for survivors or bodies.