WASHINGTON — Former Mayor Rudy Giuliani yesterday warned that homegrown jihadist terrorists — such as the Fort Hood shooter and Boston bombers — are avoiding detection because “political correctness” hamstrings law-enforcement agencies.

“We have to purge ourselves of the practice of political correctness,” he told the House Homeland Security Committee at a hearing on the evolving post-9/11 terrorist threat. “You can’t fight an enemy you don’t acknowledge.”

He mocked the Obama administration’s description of Army Maj. Nidal Hassan’s shooting spree at Fort Hood as “workplace violence.”