Al-Qaida's deputy chief called on all Muslims to join the holy war against the West.
"May Allah pluck out your eye if you haven't yet seen that jihad is an individual duty," the transcript quoted al-Zawahri as saying.
Could be a reaction to the public relations reversals al-Qaida has been suffering in recent weeks, with Sunni leaders in Iraq turning against them (actually, that's been going on for over a year -- American news outlets had to wait until after the 2006 elections to break the story) and the Muslims in Britain feeling pressured to distance themselves from jihad.
In a strongly worded statement Dr Muhammad Abdul Bari, the secretary general of the Muslim Council of Britain (MCB), condemned the barbarity of the London and Glasgow car bomb attempts.
"Let us be absolutely clear," he said. "Those who seek to deliberately kill or main innocent people are the enemies of us all."
He pledged on behalf of the MCB "all the necessary support" to prevent "such murderous actions". He said: "When the house is on fire our responsibility is not to blame each other, it is to extinguish the flames...."
Dr Abdul Bari said: "It is our Islamic duty not only to utterly and totally condemn such evil actions, but to provide all the necessary support to prevent such atrocities taking place". He added that the events of the past few days had been "very disturbing and challenging".
Well, okay, Dr. Abdul Bari was referring specifically to terror in the UK.
"It looks sadly as if the terror threat currently facing our country will be with us for some time to come," he said at a press conference called in response to the bomb plots.
"There is no cause whatsoever that could possibly justify such barbarity. Those who engage in such murderous actions and those that provide support for them are the enemies of all, Muslims and non-Muslims, and they stand against our shared values in the UK."
One may hope that the good Doctor and his coreligionists may someday extend their outrage at and opposition to terrorist murder to those places and times when the victims are, say, Iraqis, or (dare one dream?) Americans and Israelis.