U.S. sees threat to foreign aid workers in Pakistan

"We have information of ... potential targeting of foreign relief workers in Pakistan as well as government ministries," U.S. State Department spokesman P.J. Crowley told reporters.

"Without getting into intelligence matters, we are in possession of threat information," he said. "We are talking to and working with the government of Pakistan to do everything we can to make sure that our disaster response and Pakistan's disaster response can continue in light of this threat."

Pakistan ordered fresh evacuations from Sindh province on Thursday as the country struggled to bring relief to millions already displaced by flooding.

Floodwaters are beginning to recede across the country, but because of high tides in the Arabian Sea and the possibility of more rain, the risk of flooding remains in the southern province of Sindh.