A search is under way for a missing man who jumped into the sea to rescue two children.
The man, 33, entered the water with another man to help the children, aged three and 17, who had got into difficulty close to the entrance of Portsmouth harbour, a spokesman for Hampshire Constabulary said. He said police and other emergency services were involved in the search.
The spokesman added: "We were called at 3.45pm to reports that the man had gone into the water at Tower Street to rescue two children. Both children are now out of the water as is another man who also went in to save them.
"The search for the first man is continuing in the waters around Camber Docks and Old Portsmouth, and involves the Coastguard helicopter and the Ministry of Defence police boat."
A Solent Coastguard spokeswoman said Coastguard rescue teams, the Coastguard helicopter, Gosport lifeboat, Hampshire Constabulary and Royal Navy personnel were all involved.
The spokeswoman said they had been called at about 3.40pm. She said she did not know whether any of the people involved in the incident were related to one another.
She added: "The man was last seen in the water close to the Square Tower which is pretty close to the harbour entrance. There are very strong currents, deep channels, ferries in and out and all sorts of traffic."
A woman working at The Wellington pub, who did not wish to be named, said the incident had happened on the beach across the road.
She said she believed the older man had swum out to sea to rescue two boys who were in distress.
"It's terrible. The police are still down on the beach now. Unless you were on the beach at the time you would not have seen what was happening. I hope they find him," the woman added.