
The message posted on the US embassy website identified "key government installations in the downtown area of Islamabad known as the Red Zone" and a number of local hotels.
"The US embassy in Islamabad alerts US citizens that the ministry of interior of the government of Pakistan issued a general threat alert on possible terrorist attacks in Islamabad today, Sunday".
It advised "all US citizens to avoid these areas, remain vigilant, keep a low profile, and continue to exercise caution while in Pakistan".
Interior ministry officials were not immediately available to comment.
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