Al Qaeda's second-in-command, Ayman al Zawahiri, has threatened more attacks on Britain, less than two weeks after failed bombings in London and Glasgow.
The Egyptian cleric directed his message towards British Prime Minister Gordon Brown in an audio tape posted on the Internet.
Dr Zawahri warned that his followers are ready to repeat their attacks 'until we are sure you have fully understood.'
It was not immediately possible to verify the authenticity of the 20-minute tape, which appeared on a web site used by al Qaeda-linked groups alongside a photograph of Dr Zawahiri.
The recording came just days after two car bombs were found in London and a fuel-packed jeep was rammed into Glasgow Airport in Scotland.
In the message, Dr Zawahiri also criticised Britain's controversial decision to award author Salman Rushdie a knighthood, saying Queen Elizabeth had sent a clear message to Muslims by honouring a novelist who had insulted Islam, and said the group was preparing a response.
