(CNN) -- Authorities have removed 23 passengers from a Carnival Cruise Line ship in Australia after a series of brawls, New South Wales police and Carnival said in statements.
Cellphone video from the ship shows passengers tussling with each other, and with security officers, outside a nightclub and by a swimming pool amid shouting and screams from alarmed onlookers.
Carnival said police on Friday removed "a large family group who had been involved in disruptive acts aboard Carnival Legend. Our security team responded in several instances to extremely unruly behavior by these guests. One particular altercation in the nightclub began when the group physically attacked other guests."
Police said they were told several men fought in the early morning hours Friday while the ship was about 220 kilometers (137 miles) off Jervis Bay. Security officers on the ship intervened and detained the men before notifying police, police said.
"About 1.30 p.m. (Friday), six men and three teenage boys were removed from the ship at Twofold Bay, Eden," the police statement said. "A further 14 passengers, including women and children, also left the ship. The group were transported to Canberra where other travel arrangements were made."
Neither Carnival nor police said what started the fights. Both the police and the cruise line are conducting investigations.
The remaining passengers disembarked Saturday in Melbourne after a 10-day cruise in the South Pacific, Carnival said. CNN affiliate Seven Network said the ship carried 2,100 passengers.
One passenger, Cindy Buglisi, told Seven Network that "it was horrifying, people were screaming."
Another, Jarrah Boliltho, said, "They (members of the family group) were roaming the decks just looking to pick on any Aussie they could find."
The video also shows security officers kicking passengers after they were down on the floor.
Some of the passengers told Seven Network they wanted full refunds from the cruise line.
Carnival said it would offer a 25% discount to these passengers on future cruises as a goodwill gesture.
"We have a zero tolerance approach to excessive behavior that affects other guests," the Carnival statement said. "We sincerely regret that the unruly conduct and actions of the passengers removed from the ship may have prevented other guests from fully enjoying their cruise."