Image copyright Getty Images Image caption The Britannia had been returning from a week-long cruise to Norway

A man and woman arrested over a mass brawl which broke out on a British cruise ship have been released from custody but remain under investigation.

Six people were hurt as P&O's Britannia sailed to Southampton after a week-long trip to Norway's fjords.

A 43-year-old man and a woman, 41, both from Chigwell, Essex, were arrested on suspicion of assault.

Plates and furniture were reportedly used as weapons during the incident in the early hours of Friday.

Good Morning Britain journalist Richard Gaisford, who was on board, said the violence occurred after a black-tie evening and an afternoon of "patriotic" partying on deck, when large amounts of alcohol were consumed.

Writing on Twitter, he said: "Witnesses told me they were so frightened they had to hide, as family groups fought."

Skip Twitter post by @richardgaisford The buffet area was immediately sealed off as medical teams went to help the injured. Staff told me they’d never experienced anything like it and those behind the violence were confined to a cabin for the last day of the cruise, waiting for police here in Southampton. — Richard Gaisford (@richardgaisford) July 27, 2019 Report

Mr Gaisford said he had been told by a witness the incident was sparked by a passenger taking offence at another holidaymaker dressed as a clown.

However, P&O denied there was someone dressed as a clown on the ship.

Hampshire Police said its officers attended the ship when it docked in Southampton.

A police spokeswoman said three men and three women were assaulted, with their injuries including significant bruising and cuts.