ISLAMABAD: The Chehlum of the martyrs of Karbala will be observed amid tight security across the country on Tuesday (today) with the deployment of over 10,000 army troops at sensitive places.

Though no official announcement was made by the interior ministry till late Monday night, media reports quoting unnamed officials of the Pakistan Telecommunication Authority said that mobile phone service in over 30 cities and towns, including Lahore, Rawalpindi, Karachi, Hyderabad, Sukkur, Khairpur, Peshawar and Quetta, would be suspended on Tuesday from 8am.

According to a statement issued by the Inter-Services Public Relations, more than 10,000 army troops will assist civil administration in maintaining law and order throughout the country.

Unlike previous years, the authorities are more concerned about security for the Chehlum day because of recent incidents of sectarian killings in different parts of the country.

Last month, Rawalpindi saw curfew for the first time after a clash between twosectarian groups on the Ashura day in which 10 people were killed.

The routes of main mourning processions in almost every city, particularly in sensitive ones like Rawalpindi and Karachi, have been sealed and no one will be allowed to join processions without a thorough body search.

In Rawalpindi containers have been placed to seal the procession routes. In Karachi, heavy contingents of Rangers and police havebeen deployed along the routes and around Imambargahs and mosques.

The processions will also be monitored through CCTV cameras.

Tension has gripped Rawalpindi after an announcement by the Ahle Sunnat Wal Jamaat to stage a sit-in and a rally on Tuesday.

Police have launched a crackdown against those listed as troublemakers and so far arrested more than 35 people.Federal Interior Minister Chaudhry Nisar Ali Khan, in a meeting on Sunday, directed security agencies to carry out air surveillance of sensitive places in Islamabad and put the army on alert to meet any eventuality.

He said intelligence agencies and civil armed forces were providing support to the provincial governments in their efforts to maintain peace. Any act of violence would be dealt with an iron hand, he warned.