The roughly 15-metre (50-foot) creature swam into the old port in the centre of the Mediterranean city around lunchtime and blocked the entrance, drawing a crowd of curious onlookers who watched as divers attempted to free it.
Responding to reports of a whale-like mammal which “seemed disoriented”, a spokesman for local rescue services said it was the first time police had been called to respond to such an incident.
A variety of whales, dolphins and porpoises are known to live in the Mediterranean.
Earlier this month, at least a dozen injured dolphins washed up on beaches on the southern French coast, leaving local maritime officials baffled.
