WASHINGTON, Jan. 14 (Xinhua) -- U.S. Homeland Security Secretary Janet Napolitano on Thursday called for persistent vigilance against the threat from al-Qaida after a near-disaster bombing attack in a U.S.-bound flight on Christmas Day.

    "In view of the event of Christmas Day we must remain vigilant about the continued threat we face from al-Qaida," Napolitano said in a statement. "We are taking an additional set of aviation security precautions to protect the American people."

    Enhancing aviation security became a high priority for U.S. government after a Nigerian trained and equipped by al-Qaida brought an explosive device to a U.S. international flight and attempted to set it off on Dec. 25, 2009.

    "Some of these measures include enhanced random screening, additional federal air marshals on certain routes and adding individuals of concern to our terrorist watch list system," said the secretary.

    She also expressed appreciation for "patience of all Americans and visitors to our country, and the cooperation of our international partners as well as a committed airline industry."