The U.S. State Department has issued a travel warning that urges Americans to postpone non-essential travel to Pakistan.
The warning, issued Friday, cited concerns about the possibility of terrorist activity directed against American citizens and interests.
It said al-Qaida and Taleban elements continue to operate in Pakistan, particularly along the Afghan border region.
In September of last year, bombs caused multiple injuries at two Karachi fast-food restaurants (McDonald's and Kentucky Fried Chicken) headquartered in the U.S.
In November, another bomb blast near American and other businesses in Karachi killed three people and injured 15 others.
The State Department advised U.S. citizens who travel in Pakistan despite the warning to take precautions to ensure their security and safety.