By David Schaffer BBC News Online, Manchester

Police in Manchester are embarking on their biggest ever security operation in readiness for the Commonwealth Games.

Officers have taken two years to plan their response to the potential threats which could lie in wait for the event.

Policing for the Games began in November last year and its co-ordinators have drawn from the lessons learnt by the city after the IRA bombing in 1996.

The military has been drafted in to operate under police command.

There is no intelligence to suggest there is any threat to the Games or the city

Chief Inspector Martin Gaffney, Greater Manchester Police

Preparations have not always run entirely smoothly with disagreements over how security plans should proceed between police and Games organisers.

It led to a "memo of understanding" being drawn up, which was "an understanding of each other's position", according to Chief Inspector Martin Gaffney, co-ordinator of the Games security plan.

"There is no intelligence to suggest there is any threat to the Games or the city," says Mr Gaffney.

"But with the work of all police forces around Greater Manchester, there will be greater checks on arterial roads coming into the city.

"The military will also be visible to people in the city, which is a normal part of security operations for an event of this size.

Stadium patrols

"They won't be on general patrol, but it's fair to say they will be seen around certain venues in the city."

Head for Sportscity, a mile outside the city centre, and it does not take long to spot what stepped-up security means on the street.

Drains around the stadium have been sealed

Up to a week before the Games were due to start, police officers stood 100 metres apart around the perimeter of the City of Manchester Stadium.

Officers have also increased their vigilance in the city centre, with an operations room in Piccadilly Gardens.

Mr Gaffney says officers will not be heavy-handed.

"There's a balance to be struck all the time.

"But we have to give a degree of confidence to the people of Manchester and visitors for them to feel safe and secure, without being overbearing."

Over at Manchester Airport, staff are also working to ensure customers feel safe.

A smooth-running operation is how Mr Gaffney wants policing of the Games to be remembered.