The Prime Minister met police who took part in the security operation

Sir Richard Leese thanked Mancunians for their patience during a week in which about 17,000 extra people descended on the city.

A police security cordon, taking in the G-Mex conference centre and nearby hotels, had sealed off part of the city centre to traffic.

Greater Manchester Police also thanked the public for their co-operation.

About 1,250 officers were on duty at last Saturday's anti-war demo in the city centre which passed off peacefully.

But the force was criticised by peace protesters after officers surrounded a gathering of about 70 people on Wednesday. There were two arrests.

I would like to thank the protestors and organisers, who have, in the main, worked closely with us Assistant Chief Constable Stephen Thomas

The road closures, particularly Peter Street, caused some problems for motorists trying to get into the city along Oxford Road.

Despite the minor criticisms, Sir Richard - the Labour leader of Manchester City Council - said: "It has been a fantastic week."

"The conference has been an enormous boost to the economy of the city and we have had publicity across the UK, and across the world, that we would never, ever have been able to buy.

"This conference has already encouraged other people to say, 'Oh, we'd like to come to Manchester as well'."

Prime Minister Tony Blair and Home Secretary John Reid thanked police for the security operation during a tour of the conference control room.

Security bill

Assistant Chief Constable Stephen Thomas, of GMP, paid tribute to the hard work and professionalism of those involved in the security operation.

"Conference is traditionally a time for demonstration, and there have been a number of peaceful protests. I would like to thank the protestors and organisers, who have, in the main, worked closely with us.

"I would also like to extend my thanks to members of the public and the wider community, for their support and co-operation during the protests and road closures that have taken place."