The United States has escalated its drone war in Yemen, killing 12 terror suspects in three strikes Thursday - that's 34 al Qaeda suspects killed by drones in less than two weeks.
The action comes amid an ongoing global terror alert.
This week the United States and Britain evacuated diplomatic staff from Yemen's capital after learning of a threatened attack.
Meanwhile, 19 diplomatic posts in the Middle East and Africa have been temporarily closed.
The State Department is now urging Americans not to travel to Pakistan. Non-essential personnel in Lahore were ordered to evacuate in response to a specific threat.
Officials say al Qaeda may be getting help from the nearly 2,000 prisoners who recently escaped from jail in Iraq, Libya, and Pakistan.
"It's prudent to protect lives and it's certainly important to keep the terrorists from being able to carry out a truly devastating attack," former counterterrorism coordinator Daniel Benjamin said.
Former Homeland Security Director Michael Chertoff said, "It's possible they could be suicide bombers. It's possible they could become combatants. Some of them may have capabilities in terms of bomb making which is always of concern."
Meanwhile, Saudi Arabia has arrested two foreigners who have ties to al Qaeda in Yemen. Saudi police said they were plotting "imminent suicide" attacks in the region.