As uprisings challenge the old order in the Middle East and North Africa, one organisation which for many years claimed it was at the vanguard of toppling authoritarian regimes has so far played almost no part. So is al-Qaeda still relevant? Do the uprisings represent a threat or an opportunity to its role?

In the short term, al-Qaeda has proved slow to respond and is struggling to make any impact, its ideology of violence undermined, experts believe.

But out of the current chaos and instability in the region, they warn, it could still be able to find new opportunities.

"Ayman Al-Zawahiri (al-Qaeda's number two) has been trying to overthrow Egyptian regimes for the last 30 years by violence, and a group of middle-class activists armed with cell phones managed to achieve it in under one month," argues Nigel Inkster, a former deputy head of Britain's intelligence service, now with the International Institute for Strategic Studies.

"This is hardly a resounding endorsement for the jihadist business model."