“The terrorist threat facing our country has evolved significantly in the last ten years -- and continues to evolve -- so that, in some ways, the threat facing us is at its most heightened state since those attacks,” Napolitano said in testimony to the House of Representatives Homeland Security Committee. - Photo by AP

WASHINGTON: US Homeland Security Secretary Janet Napolitano on Wednesday warned that the threat of terrorism against the United States was in some aspects “at its most heightened state” since the Sept. 11, 2001 attacks.

In addition to the threats by al Qaeda, the militant group behind the attacks nearly a decade ago, Napolitano said the country faces new threats from those inspired by the group and those already inside the United States.

“The terrorist threat facing our country has evolved significantly in the last ten years -- and continues to evolve -- so that, in some ways, the threat facing us is at its most heightened state since those attacks,” Napolitano said in testimony to the House of Representatives Homeland Security Committee.

She also said that US officials believed there may be individuals who want to carry out attacks already in the country and that “they could carry out acts of violence with little or no warning.”

Individuals associated with al Qaeda and the Taliban have tried to carry out several attacks against the United States, including by a Nigerian man who allegedly tried to blow up a US airliner with a bomb hidden in his underwear and another individual who plotted to attack the New York subway system.

“As I have said before, we cannot guarantee that there will never be another terrorist attack, and we cannot seal our country under a glass dome,” Napolitano said in her prepared testimony. “However, we continue to do everything we can to reduce the risk of terrorism in our Nation.”