Australian police arrested 12 Greenpeace activists after an Apec protest at Newcastle, the world's biggest coal export port, as authorities again warned protesters against violence at Sydney's Apec summit.
New South Wales state premier Morris Iemma said the full force of the law would be used against violent protesters at this week's Asia Pacific Economic Co-Operation (Apec) gathering.
Australian authorities are staging the nation's biggest ever security operation for Apec, which is to be attended by 21 leaders including US President George Bush.
"I accept the commentary that is being made from a number of groups who have said they want to incite violence," said Iemma told reporters on Sunday.
"My message to them is, don't. But if you do the police will be out in force and they'll enforce the law and they'll do so with strength and authority," said Iemma.
Thousands of protesters plan to rally in Sydney during the Apec meetings to demonstrate against the Iraq war and global warming. Apec officials began the first meeting on Sunday.
Authorities have erected a five kilometre security fence across the central business district to isolate the leaders in the Sydney Opera House and nearby hotels.
Environmental group Greenpeace staged an Apec protest on Sunday on a coal ship in the port of Newcastle, north of Sydney. Greenpeace unfurled a banner written in Chinese urging Beijing to be aware of efforts to undermine the Kyoto Protocol by Australia and the United States.
Both Australia and the United States are opposed to Kyoto, arguing its effort to cut greenhouse gas emissions is flawed as it excludes some of the world's biggest polluters, like India.
"Greenpeace is calling on Apec countries to reject (Australian Prime Minister) John Howard's efforts to undermine the Kyoto Protocol through his calls for "aspirational targets'," said Greenpeace campaigner Ben Pearson.
Howard is opposed to setting targets for greenhouse gas reduction, arguing it would damage the Australian economy which is heavily reliant on coal-fired power. He prefers to talk of "aspirational targets" for individual nations.
"Australia's climate policy is to push export coal and to hell with the consequences for the planet," said Pearson.
"Real action on climate change means moving away from coal and shifting to clean, renewable energy and we don't have the luxury of time for expensive talkfests that have no concrete outcomes," said Pearson.
Malaysian Trade Minister Rafidah Aziz, who will attend Apec, said last week that the absence of Australia and the United States from Kyoto meant they lacked the credentials to lead climate change talks at this week's Sydney meetings.
Australian security officials say they have received no intelligence of a terrorist threat to Apec and the nation's counter-terrorism alert remains unchanged at medium, which means a terrorist attack could occur. Australia, a staunch US ally, has never suffered a major peace-time attack on home soil.
But authorities unveiled an emergency public communications system on Sunday in case of a major incident. Flashing message boards have been erected at 14 locations across the city and loud speakers at 49 sites.
Fighter aircraft and police helicopters are enforcing a 45-nautical-mile restricted air space over Sydney and will intercept any unauthorised aircraft. A total of 5,000 police and troops are patrolling the city centre.