US embassies: 'You can let Al-Qaeda know that you know'

The US says it will keep a number of embassies in north Africa and the Middle East closed until Saturday, due to a possible militant threat.

Twenty-one US embassies and consulates closed on Sunday.

The state department in Washington said the extended closures were "out of an abundance of caution", and not a reaction to a new threat.

BBC security correspondent Gordon Corera said the US authorities had to take action after last year's attack on the US consulate in Benghazi, Libya, where the US ambassador and three other Americans were killed.

However, he explained there were other reasons for disclosing the threat, beyond justifying the closures: "By talking about this [threat] you can disrupt the potential plans, you can let Al-Qaeda know that you know what they might be doing... Which leads to more intelligence."