Delhi police say they have “meticulous” plans in place to protect Commonwealth Games visitors, including deploying helicopter-borne snipers and putting a four-layer security cordon around key venues and the athletes village “There will be surveillance from the skies and deployment of quick reaction teams, special commandos and snipers to keep a hawk-eye vigil over the city,” police spokesman Rajan Bhagat told India Real Time on Thursday.

In recent months concerns have been raised about the effects of construction delays, corruption, rain and dengue and even the theme song on the success of the Games.

Now, as the Games draw near, concerns about a possible terror attack during the competition from Oct. 3 to 14 are increasing. India has suffered major terror attacks in the past including a shooting and hostage-taking at several locations across Mumbai, among them top hotels, in 2008.

In a travel alert issued on Sept. 1 the U.S. State Department told its citizens to carefully monitor local news reports for threats if traveling to India during the Games.

But the U.S. seemed as concerned about commuting in the Indian capital as terrorism in its alert. “U.S. citizens are advised to take care when traveling within Delhi,” said the State Department. “While many of Delhi’s roads and public transport systems have been upgraded for the Games, some roads remain poorly maintained, which can cause traffic delays and accidents.”

In August, Australia said in a Commonwealth Games bulletin, “Australians in New Delhi should be aware that the Commonwealth Games will be held in a security environment where there is a high risk of terrorism.”

One Indian official has said Islamic militants could be planning paraglider attacks on the Games.

Explaining the four tiers of security, Mr. Bhagat said the police are creating exclusive outer, middle and inner security zones. Vehicles will be restricted to the outer zone, after which security personnel will ferry spectators to have their barcoded tickets read and then to their designated seats. Every spectator attending the opening and closing ceremonies will be photographed before being allowed to enter, he said.

Sportsmen, officials and guests can enter on special security-screened buses and only heads of state will allowed to take personal cars into the venues.

“We are not only looking into the security aspects of the venues but also every aspect of the city’s security,” said Mr. Bhagat.

As part of security procedures, balloons, coins, torn paper and hockey sticks won’t be allowed into the venues (but do the hockey players know that?). A report Thursday suggested pens could be added to the list.

Delhi police have been trained on improving their communication skills and etiquette, as well as in how to frisk and search people and screen baggage. Paramilitary troops will also help city officers in policing the venues.

Mr. Bhagat spoke to India Real Time after Indian Home Minister P. Chidambaram reviewed security arrangements for the Games with senior government and security officials on Wednesday.

“All security overlays were expected to be in place by Sept. 15 after which another review would be held,” Mr. Chidambaram told reporters, who have been asking about delays in the security preparations.

The first batch of athletes and officials are supposed to start arriving in New Delhi from Sept. 10. Over 10,000 athletes from 71 countries are expected to participate.