WOODBURY - One day after the CIA assassinated two key al-Qaida leaders in Yemen, the U.S. government is warning of possible retaliation by the terror network.U.S. officials say Anwar al-Awlaki and Samir Khan had an almost cult-like following among radicalized American Muslims. "The concern now is that one or more of those Americans would try to avenge his killing," says Homeland Security Committee Chairman Rep. Peter King (R-Seaford). King says considering the fact that Khan was from Long Island and Awlaki himself was focused on targeting New York, local police must remain on heightened alert. In New York City, law enforcement is also ramping up after a photo of Grand Central Station was featured in the last edition of Khan's "Inspire." According to a bulletin from the FBI and the Department of Homeland Security obtained by CNN, initial reports of Awlaki's death generated a relatively high level of interest on extremist websites.Michael Balboni, the former New York State Homeland Security advisor, argues that homegrown terrorists might not retaliate as quickly as feared."It's rare that you just suddenly decide to go out and plant a bomb and run away," he says.