The Department of Homeland Security is urging fans at professional sports events to help keep the country safe by reporting anything suspicious they see.

Homeland Security Secretary Janet Napolitano joined New York Police Department Commissioner Raymond Kelly on Monday to announce the security effort. It's an expansion of the Homeland Security campaign "If You See Something, Say Something."

The words were coined by the NYPD as a security slogan for the city's transit system after the Sept. 11 terror attacks.

Kelly and Napolitano announced the plan at a news conference along with NBA Commissioner David Stern and Major League Soccer Commissioner Don Garber.

Napolitano says citizens play a critical role in reporting suspicious activities and threats. She says information will be shared with officials trying to avert security breaches.