US president Barack Obama has ordered that all appropriate steps be taken to protect Americans in response to a threat of an al-Qaeda attack.
One day after announcing it would close a number of embassies across the Islamic world on Sunday, the US State Department issued a worldwide warning that al-Qaeda may attack in August.
It said attacks were possible particularly in the Middle East and North Africa, and possibly occurring in or emanating from the Arabian Peninsula.
The worldwide travel alert for US citizens warned of the potential for terrorists to attack public transportation systems and other tourist infrastructure.
