Pakistan is to suspend mobile phone services in most parts of the country over the next two days to prevent attacks against Shiite Muslims during a key religious commemoration.
Militants often detonate bombs using mobiles and the Pakistani government has implemented similar service suspensions in the past, but not on such a wide scale.
Saturday and Sunday are the most important days of Muharram, the first month of the Islamic calendar, which is especially important to Shiites.
Pakistani Shiites on Sunday observe the Ashoura, commemorating the 7th century death of Imam Hussein, the Prophet Mohammed's grandson. The Sunni-Shiite split over the true heir to Mohammed dates back to that era.
Different parts of the Muslim world mark Ashoura on different days - neighbouring Afghanistan observes it on Saturday.
Several bombings targeting Shiites earlier this week killed over a dozen people.
The suspension will begin at 6am on Saturday and run through the next day, Interior Minister Rehman Malik told reporters in Pakistan's capital, Islamabad.
He said 90% of the bombs set off by militants in Pakistan have been detonated using mobiles.
Some commentators have criticised the government for the policy saying it was a huge inconvenience to millions of Pakistanis and that militants could find other ways to stage attacks.
www.interior.gov.pk (Pakistan Interior Ministry)