The government issued a travel alert Wednesday, warning against all travel to parts of the country bordering Afghanistan and all but essential travel to most of the surrounding areas.
The government warning said there was a high threat of terrorism and sectarian violence throughout Pakistan.
"In the days immediately following traditional Shiite processions on the 21st day of Ramadan, which this year is July 31, there have been violent sectarian conflicts," the warning stated. "There is a possibility that this may occur again this year."
The Muslim holy month of Ramadan ends with Eid al-Fitr, which falls Aug. 9 this year.
Pakistan this week confirmed Mamnoon Hussain will take over for President Asif Ali Zardari in September. The presidency is a largely symbolic post as most powers are in the office of the prime minister.
Zardari moved powers to the prime minister when he took over from Pervez Musharraf, who stepped down in 2008. Musharraf is set to be indicted next week for the 2007 assassination of his rival and former Prime Minister Benazir Bhutto.