al-Qaeda takes blame for London blasts

The Egyptian-born militant also criticized the legitimacy of Sunday's parliamentary elections in Afghanistan and condemned Pakistan the one-time ally of Afghanistan's deposed Taliban regime for forging strong ties with the United States.

"The blessed London attack was one which al-Qaeda was honoured to launch against the British Crusader's arrogance and against the American Crusader aggression on the Islamic nation for 100 years," al-Zawahri said in the tape aired on Qatar-based al-Jazeera TV.

"In their final testament, the heroic brothers in the London attacks ... provided great lessons to the Islamic nation and Muslims in Pakistan to oppose the infidels," said al-Zawahri, who wore a black turban and white shirt and spoke to someone off-camera who was interviewing him. The attacks also killed the four bombers.

"This blessed attack revealed the real hypocritical face of the West," said the bushy gray bearded al-Zawahri in his latest tape, which included English subtitles and credits saying it was produced and translated by al-Sahab Media Production House, a shadowy purported al-Qaeda media organisation.

While there was no immediate way to verify al-Zawahri's claim, the attacks on three London underground stations and a double-decker bus bore all the hallmarks of the terror group.