The United States embassy in Islamabad asked its nationals and officers in Pakistan not to visit the northwestern's Peshawar city in the next 24 hours due to security concerns, a U.S. embassy notification said on Tuesday, Xinhua reported.
The U.S. nationals were also asked to avoid visiting public places and that they should not inform anyone about their routes, according to private Geo TV channel.
The U.S. embassy asked its nationals to take steps for their security. They were also asked to keep their documents all the time.
Security forces are fighting militants in the northwestern part of the country and Taliban earlier warned that they would carry out attacks in some major cities.