Crews in Sydney, Australia are building a 5.5-kilometre steel-and-concrete fence to keep demonstrators and delegates apart at next week's APEC summit.

The Sydney Opera House and hotels that will house more than 5,000 delegates will be hidden behind the barrier for the Sept. 2-9 meetings.

The security fence will shut down part of Sydney's central business district.
(Rob Griffith/Associated Press)

There were traffic disruptions as work continued on the three-metre-high fence Saturday, a day ahead of the official start of the APEC summit, which culminates in the leaders' meeting next weekend.

Police expect violent protests against the war in Iraq and on climate change, but according to critics, the security measures are designed to frighten those thinking about attending the demonstrations.

"This is part of a seriously intense intimidation campaign, the likes of which I have never seen in my experience before," said rally organizer Alex Bainbridge.

About 3,500 police, backed by 1,500 counter-terrorism and special forces soldiers, will ensure protesters stay away from the security zone marked by the fence.

The APEC summit is one of the largest gatherings of world powers and will be the biggest international meeting Australia has ever hosted.

"Right now, there's one priority, there's one show in town and that's APEC," New South Wales state police Commissioner Andrew Scipione told reporters on Saturday.

"APEC must be delivered. It's the biggest security event we've ever had in this nation," he said.

Prime Minister Stephen Harper is due in Sydney next weekend. He will follow that trip with an official visit to Australia and become to first Canadian prime minister to address the country's parliament.

International Trade Minister David Emerson and Foreign Affairs Minister Maxime Bernier will be in Sydney on Wednesday and Thursday for ministerial meetings.

U.S. President George W. Bush arrives Tuesday and is scheduled to meet one-on-one with leaders from Australia, China, South Korea, Japan and possibly Russia.

Global warming and trade will top the agenda at the forum. The 21 regional leaders are also likely to discuss North Korea and Iraq.