DUBAI - Al Qaeda has claimed responsibility for the kidnapping of an American man in Pakistan and demanded the release of prisoners and an end to air strikes in Muslim countries in exchange for his freedom, according to the SITE online monitoring service.

SITE said the announcement was made in a recording by al Qaeda leader Ayman al-Zawahri posted on an Islamist website and monitored on Thursday.

"Just as the Americans detain all whom they suspect of links to al Qaeda and the Taliban, even remotely, we detained this man who is neck-deep in American aid to Pakistan since the seventies," SITE quoted Zawahri as saying in the recording.

Assailants kidnapped Warren Weinstein, an American development expert, in August in the Pakistani city of Lahore, according to a top Pakistani police official.