WASHINGTON, Nov. 30 (Xinhua) -- The U.S. Department of Homeland Security warned financial companies on Thursday that al-Qaida might be planning cyber attacks on banking and financial institution Web sites.

    The threat apparently was posted on a Web site, and was discovered by the department on Monday, a report posted on CNN's Web site quoted Homeland Security Department spokesman Russ Knockeas saying.

    The department decided to send an advisory out to financial institutions out of caution, Knocke said.

    The department nevertheless had no evidence to verify the threat.

    "There is no information to corroborate this aspirational threat," said the spokesman.

    The report said the threat warned that denial-of-service attacks would be launched against U.S. stock market and banking Web sites during the month of December.