Christians Under Attack

In a video message, Ayman al-Zawahri, Osama bin Laden's deputy, hit out at Mr Bush for trying to kill him this month and taunted him by asking, "Do you know where I am?"

In a video sent to the Qatar-based al-Jazeera TV by courier, Zawahri called the president a "butcher", "liar" and a "failure" over a CIA missile strike on January 13 in eastern Pakistan by a Predator drone.

US Government officials say the unmanned drone killed four high-ranking al-Qaida operatives among 13 victims.

Zawahri did not confirm that some of his top aides were killed. He invited Mr Bush to become a Muslim.

"Should you accept, you become a brother and God forgives you all that is past," he said.

Opinion is divided over what the message signals.

"He took risks to get this out quickly, which is a measure of his anxiety," said Vince Cannistraro, a former CIA counter-terrorism chief, who said most tapes take at least six weeks to reach media groups.

Mohamed Salah, the Cairo bureau chief for the Arabic-language daily newspaper, said the speed of Zawahri's response – not the message – was most surprising.

"Ayman Zawahri is telling us he's in a location where he can follow the news, that he knows what the Americans are doing and that they can't catch him," Mr Salah said.

Referring to bin Laden's truce plea in a January 19 tape, which Mr Bush rejected, Zawahri said bin Laden "offered you a decent exit from your dilemma but your leaders . . . insist on throwing you in battles and killing your souls in Iraq and Afghanistan and – God willing – on your own land".

"Butcher of Washington, you are not only defeated and a liar, but also a failure," he said.