The threat of suicide bombers means the event faces unprecedented potential dangers, according to Gerry O'Connell, the former Deputy Chief Constable of Lancashire.

Dave Martin, 62, of South Shields, has been to the Indian capital before, for the World Half-Marathon Championships in 2005, and said it's "back to the sharp end again".

But the international athletics correspondent for Press Association Sport added: "You can't consider not going because of the security threat.

"Of course it is serious and I will be taking it very seriously, but you have to hope that the authorities there are going to ensure the safety not only of the media, but primarily of the athletes and thousands of spectators from all the member nations."

The Indian Government has promised extensive measures will be taken during the Games, including exclusive lanes for vehicles, four-layered security checks at venues, experts to battle chemical or biological weapons and helicopter surveillance.

But Mr O'Connell, who had a senior role at Lancashire Constabulary when the IRA detonated a bomb in Manchester in 1996, told a counter terrorism conference in India that terror organisations will pose severe threats during the Games.

He said: "Intelligence inputs would suggest that the Games are likely to targeted by groups, big or small.

"Targetting such an event would give a terrorist organisation the kind of recognition they yearn for."

Terrorism in India is primarily attributed to Islamic, Hindu, Sikh, Christian and Naxalite radical movements and an estimated 800 terrorist cells are operating in the country.

Mr Martin, who served in the Army for 23 years, said: "When I was there in 2005 I would say it was a little bit unstable then because there were tanks on major crossing points in the city.

"It is a worrying situation, but with my past military experience, I will just stay alert in everything I do and be careful."