Police say the intensity of the violence and the number of attacks on police are the biggest concern after the first night of a national operation targeting alcohol-fuelled violence.

Almost 500 people have been arrested around the country since Operation Unite began on Friday night.

New South Wales police arrested 251 people - 27 of those allegedly assaulted police, leaving one officer with a broken nose.

"The purpose of this operation is to ram home the message that police and the wider community have had enough of alcohol-related violence," operation commander Assistant Commissioner Denis Clifford said.

In Queensland more than 400 officers were out in force arresting 137 people, including one man in Mackay who has been charged for allegedly biting a police officer.

Police in Victoria arrested 44 people - 39 for drunkenness and five for assault.

Police in Western Australia charged 227 people with a total of 245 offences, including assault, disorderly behaviour and drug possession.

WA Police Commissioner Karl O'Callaghan says officers will take a zero tolerance approach in the national operation over the weekend.

"We've seen an intensity in the level of assaults happening on the streets," he said.

"We've seen one-punch assaults, we've seen glassings and a whole range of things that concern us.

"This is a way of sending a very strong message to the community that it is unacceptable."

Fourteen arrests were made in South Australia, while in Tasmania nine people were arrested, mainly for drink driving.

Five were arrested in the ACT. Figures for the first night of the operation in the Northern Territory have not been released.

Operation Unite has been held three times over the past two years and police expect another will be conducted in December.

Across Australia and New Zealand there were about 2,617 arrests during the December 2010 operation.

- ABC/AAP