Sydney is in the grips of an unprecedented security operation as the Australian city plays host to the Asia-Pacific Economic Co-operation forum.
Twenty-one leaders from the Asia-Pacific region are in town for the summit.
A 5km (three-mile) barrier has been erected across the central business district, sealing off the summit venue.
Five-thousand police officers and troops are on patrol, on water as well as land.
Police helicopters are on guard around the hotel where US President George W Bush is staying.
Even the famous Sydney Opera House is bristling with snipers.
Many residents are trying to ignore the disruption and just get on with daily life.
But many have simply steered clear of the city centre. Here the normally bustling cafes of Circular Quay stand empty.
As expected the summit has drawn crowds of demonstrators, many of them campaigning for more action on climate change.
President George W Bush and the US involvement in Iraq have been singled out for particular attention.
With so many issues to flag up demonstrators have had to resort to eye-catching tactics to get their message across. Here a group stages a "Bums for Bush" protest.