While there was a tense standoff between police and demonstrators at one event and a single arrest, the protests were largely peaceful as more than 5,000 police and troops patrolled the city.

Activists said the security clampdown for the Asia Pacific Economic Cooperation summit had forced them to get creative when making their point, as authorities had restricted traditional activities such as marches.

Without doubt the cheekiest protest was an event called "Bums for Bush", where anti-war organisers said they wanted to lay down the bottom line for visiting US President George W. Bush over the war in Iraq.

They failed to get the 2,000 behinds, or 4,000 cheeks, required to set the world record for mooning but said they made their point with a "21-bum salute" for Bush, with one posterior for every government represented at the summit.

Letters painted on some of the bottoms spelled out "bums not bombs", raising cheers from about 450 onlookers.

"We want to put Bush on his arse," mooning protester Jeff Halliday told AFP as he buttoned up his trousers. "It's a serious issue but it helps to have a laugh about it."

A group of surfers at Sydney's iconic Bondi Beach kicked off a series of protests Friday by groups concerned over a range of causes, including climate change and the Iraq war, or simply unhappy with Bush's presence Down Under.

About 75 surfers, many wearing wetsuits to ward off the spring morning chill, gathered on the Bondi sands at sunrise around a huge banner demanding APEC endorse binding targets for reducing the greenhouse gases blamed for global warming.

Greens senator Kerry Nettle maintained the beach theme when she held a press conference in the heart of Sydney's financial district flanked by 21 supporters dressed as surf-lifesavers.

Nettle said police had initially banned her event, even though it is not near the three-metre (nine foot) fence that has been built through the middle of the city to create an exclusion zone for visiting dignitaries.

"The police operation is overkill," she said. "I'm glad the police, albeit belatedly, saw sense and allowed this peaceful event to proceed."

The news conference went ahead with the 21 mock lifeguards, many of them elderly, watched by about 30 police with a riot squad vehicle parked around the corner.

At nearby Hyde Park, which has been the site for many of this week's protests, the Solidarity Choir belted out left-wing anthems to a crowd of about 60 faithful who braved a steady drizzle to make their views heard.

Paul Murphy, from the Sydney Peace and Justice Coalition, said numbers were down because of the massive security operation.

"There's been a series of increasingly hysterical comments from the prime minister (John Howard) and police that has led many people to think that they'll be arrested just for setting foot in the city," he said.

The government declared a special public holiday Friday to keep most people out of the centre of town as the presidents and prime ministers whizz about in huge motorcades.

The protests were mostly been peaceful, but there was a minor scuffle when some pro-Bush demonstrators arrived, resulting in a man being arrested and charged with assaulting police.

There was also a standoff when demonstrators spilled onto a road after "Bums for Bush", prompting police to use motorcycles with lights flashing and sirens blaring to nudge them onto the pavement.

The main APEC protest is scheduled for Saturday, a march through the streets that police have estimated could attract 20,000 demonstrators.

All rights reserved. copyright 2018 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.