Bin Laden's deputy says US beaten in Afghanistan

The man considered to be Osama bin Laden's deputy has declared America has been beaten in Afghanistan and al-Qa'ida fighters are still waging war against all US citizens.

In an audiotape broadcast by the al-Jazeera Arab news channel, Ayman al-Zawahiri, said: "America has been defeated [by] our fighters despite all its military might, its weaponry. With God's help, we are still chasing Americans and their allies everywhere, including their homeland."

US authorities are studying security warnings, including one about New York. A White House spokesman, Scott McClellan, said: "We have remained concerned about the volume of reporting of threats and that is why the Department of Homeland Security has sent out bulletins to homeland security officials and law enforcement personnel, urging all to continue be on a heightened state of alert."

An intelligence official said: "There has been a threat to New York city. We are trying to determine its credibility and trying to corroborate it."

The US navy is said to have seized a boat in the Persian Gulf carrying two tons of hashish and four al-Qa'ida suspects.