The flames created a vast plume of smoke over the city, but authorities reported that the fire had been brought under control on Wednesday.
Firefighters have been battling a large blaze at the historic port of Ancona on Italy's Adriatic coast.
The fire has caused significant damage to the port, but no injuries have been reported by authorities.
According to initial investigations, the fire started in the early hours of the morning at 00.30 on Wednesday in one of the warehouses and spread rapidly in the port area.
It is not yet clear what caused the initial blaze, which created a vast plume of smoke over the port city.
Sixteen fire crews had attended the incident, including from the nearby towns of Macerata and Pesaro.
The Italian fire brigade reported on Twitter that "several shipbuilding sheds" were damaged by the fire, which had spread to an area of around 20,000 square metres.
"The fire itself is under control, the firefighters have managed to contain it and prevent it from spreading to other buildings, plants, companies and other nearby activities," said the Mayor of Ancona, Valeria Mancinelli, on Facebook.
Authorities had said that it would be a "long operation" to completely extinguish the fire due to difficulties in reaching the worst affected areas.
The municipality has closed all schools, universities, parks, and outdoor sports facilities as a precaution, pending analysis and indications from the health authorities.
Citizens have also been advised to limit their movements and close building windows.
"At the moment we have no indication about the alleged toxicity of the cloud," said Mancinelli.
"Please avoid the circulation of unreliable news that can only generate confusion."