The State Department has banned all US personnel from staying at or even visiting major hotels in Pakistan's capital and two other cities over fears of new attacks following the deadly truck bombing at the Marriott hotel in Islamabad.
US government employees have also been told to stay away from public restaurants in the three cities and limit their trips to shopping markets. The US Embassy in Islamabad is advising other Americans working or visiting there to take the same precautions.
"Effectively immediately, US government personnel are no longer permitted to stay or frequent major hotels in Islamabad, Karachi and Peshawar," a notice from the US Embassy in Islamabad said.
"There are reports that further terrorist attacks may take place in Islamabad, and that markets and restaurants may be among the intended targets."
The ban on hotel stays applies only to government employees, who frequently used the Marriott.
The notice repeats warnings to Americans to maintain a low profile in public while in Pakistan, avoid crowds and demonstrations and vary their travel routes and times.
The notice was issued late on Tuesday amid concerns that militants may seek to repeat the carnage of Saturday's attack on the Marriott that killed 53 people, among them the Czech ambassador and two US Defense Department employees, and wounded about 270 others.