Yemen security blitz as staff leave

The Yemeni government has revealed reasons for the intense security alert that led to all US citizens being ordered out of the country on Tuesday.

Al Qaeda planned a massive and complex plot to seize parts of Yemen's critical infrastructure and blow up oil pipelines.

It says the plot was timed for the twenty seventh day of Ramadan.

Al Qaeda members dressed as soldiers would have taken over several cities.

Davis Willis reports from Washington.