Known al-Qaida affiliated websites are warning Muslims to leave New York, Washington, D.C., and Los Angeles ahead of massive attacks it claims have been planned for those cities.

The statements, posted on sites such as Al-Lewa – Arabic for "The Banner" – are part of the alarming increase in "chatter" among terrorist operatives in recent weeks cited by Homeland Security officials for raising the terror threat level to high, or orange, reports the New York Post.

Officials told the paper the CIA, FBI and National Security Agency consider the messages "pieces of the overall puzzle."

Counterterrorism experts uncovered and translated statements boasting of an impending wave of terror that started Nov. 15 after the suicide bombings in Istanbul, Turkey.

"The next al-Qaida attacks will be most violent and will target the U.S.," read one claim translated by Rita Katz, director of the SITE Institute.

"Our Muslim brothers in America, this is our final warning. We ask you, as fast as you can, to leave the following cities immediately: Washington, D.C., New York City, Los Angeles," read a second message posted Thursday by a group calling itself the Islamic Bayan Movement.

According to the messages, the jihadists apparently are pleased with the terror alert issued by government agencies and the anxiety it prompts for travelers this holiday week.

Katz said one message published quoted al-Qaida's mouthpiece, the Global Islamic Media Society, in saying it took delight that Americans are now "living in a state of anxiety and constant fear."

"You will forget about Manhattan events. Be prepared," the statement concluded.

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