Al-Qaeda's intensifying propaganda war with the US and Europe has become as important to the movement as terrorist attacks on western cities and interests, according to analysts studying a video featuring one of the London suicide bombers.

The tape of the last testimony of Mohammad Sidique Khan, broadcast by al-Jazeera television on Thursday, also featured Ayman al-Zawahiri, the al-Qaeda second in command, claiming its campaign had shifted to "the enemies' land".