The city’s high-tech counterterrorism monitoring system is being expanded from Lower Manhattan into Midtown.

The network of security cameras, license plate readers and weapons sensors known as the “Ring of Steel” will now cover Penn Station, Grand Central Terminal and Times Square.

The system began last year and currently covers two square miles downtown and includes the New York Stock Exchange and the World Trade Center site.

“Most times, you will either prevent it because you’ll catch somebody or you’ll prevent it because you’re scaring people away. If people know, if people read about this system, they might very well decide to take their nefarious affairs elsewhere or just not do it,” said Mayor Michael Bloomberg.

“This system here will build uses and will build on predictive software. Let’s say a truck goes around the block three times. Well, you can set off an alarm at that level,” said Police Commissioner Ray Kelly.

The city plans to add the technology to key spots between 30th and 60th streets.

The expansion is projected to cost about $24 million in federal money.

Meanwhile, police chiefs from big cities across the nation are backing an anti-terrorism program that educates people on when to report suspicious behavior.

It comes after a store clerk expressed concern and curiosity as to why terror suspect Najibullah Zazi bought large quantities of beauty supply products.

Officials say that type of civilian vigilance is needed in the collective effort to fight terrorism.

Authorities are now pushing to adopt an i-Watch program that would educate and encourage civilians on what they should be looking out for.

Federal authorities allege Zazi tried to make a homemade explosive from ingredients he bought at Denver-area stores.

Zazi is being held without bail on charges of conspiracy to detonate a weapon of mass destruction.

He has pleaded not guilty to the charges.

(Source: NY1)