An audiotape allegedly recorded by a top al-Qaeda leader has accused US President George W Bush of exaggerating his successes in the "war on terror".
The hunt goes on for both Zawahiri and Bin Laden
The tape aired by Arabic television al-Jazeera was reportedly made by Ayman al-Zawahiri, a fugitive Egyptian cleric thought to be Osama Bin Laden's deputy.
According to the tape, Mr Bush had lied when he said his troops had "arrested more than two-thirds of al-Qaeda".
President Bush recently said US forces were effectively unravelling al-Qaeda.
The audiotape also attacked other recent assertions from the American president - regarding Iraq and Afghanistan.
"Iraq does not enjoy freedom and security but has gone from the tyranny of a secular dictator... to that of a crusader occupier hostile to Islam," says the voice on the tape.
Nor, according to the speaker, is the situation in Afghanistan any more stable.
"Otherwise," it asks, "from where are we carrying out attacks on your forces and your agents, from where are we sending our messages which defy you and reveal your lies?"
US officials believe Mr Zawahiri and Osama Bin Laden are probably in the mountainous border region of Afghanistan and Pakistan.
The tape told the US to expect more attacks along the lines of the 11 September 2001 hijackings.
"Legion after legion" of Muslim fighters were gearing up to target the US, the tape announced, advising President Bush to "strengthen your defences".
The US leader was lambasted for making no mention of the economic damage apparently wrought by al-Qaeda's actions and for "ridiculing" his audience with "deceptions and lies".
In another tape aired on Tuesday by the al-Arabiya television network, a speaker - again thought to be Mr Zawahiri - attacked France's decision to ban Muslim students from wearing headscarves in schools.
It is not clear whether both al-Arabiya and al-Jazeera released recordings from the same original tape - or indeed, how the recordings fell into their possession.
The authenticity of the recordings has not been confirmed - but experts say the tone and angry rhetoric match earlier messages attributed to Ayman al-Zawahiri.