A army truck goes through a security checkpoint on the approach to the parliament building in Islamabad
A army truck goes through a security checkpoint on the approach to the parliament building in Islamabad August 13, 2014. Thousands of riot police sealed off Pakistan's capital with barbed wire and shipping containers on the eve of the country's Independence Day, in a bid to foil mass protests aimed at toppling embattled Prime Minister Nawaz Sharif. REUTERS/Caren Firouz (PAKISTAN - Tags: POLITICS CIVIL UNREST MILITARY)
A couple walks on a major highway in front of containers placed to block roads in Islamabad
A couple walks on a major highway in front of containers placed to block roads in Islamabad August 13, 2014. Thousands of riot police sealed off Pakistan's capital with barbed wire and shipping containers on the eve of the country's Independence Day, in a bid to foil mass protests aimed at toppling embattled Prime Minister Nawaz Sharif. REUTERS/Faisal Mahmood (PAKISTAN - Tags: POLITICS CIVIL UNREST)
Siege mentality grips Pakistan ahead of Independence Day
PAKISTAN-POLITICS/PROTESTS (PIX):Siege mentality grips Pakistan ahead of Independence Day
A crane moves containers, to be used to block roads during a planned protest march, in Islamabad
A crane moves containers, to be used to block roads during a planned protest march, in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Faisal Mahmood (PAKISTAN - Tags: POLITICS CIVIL UNREST)
A police officer keeps watch as vehicles go past containers, to be used to block roads during a planned protest march, in Islamabad
A police officer keeps watch as vehicles go past containers, to be used to block roads during a planned protest march, in Islamabad, August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Faisal Mahmood (PAKISTAN - Tags: POLITICS CIVIL UNREST)
A crane places containers, to be used to block roads during a planned protest march, along a road in Islamabad
A crane places containers, to be used to block roads during a planned protest march, along a road in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Faisal Mahmood (PAKISTAN - Tags: POLITICS CIVIL UNREST)
A motorcyclist takes a detour around a bridge, seen with containers to be used to block roads during a planned protest march, on a major highway, in Islamabad
A motorcyclist takes a detour around a bridge, seen with containers to be used to block roads during a planned protest march, on a major highway, in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Caren Firouz (PAKISTAN - Tags: POLITICS CIVIL UNREST)
Pedestrians walk around a container, which will be used to block roads during a planned protest march, in Islamabad
Pedestrians walk around a container, which will be used to block roads during a planned protest march, in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Caren Firouz (PAKISTAN - Tags: POLITICS CIVIL UNREST)
A woman walks on a major highway as containers, which are to be used to block roads during a planned protest march, are seen in the background, in Islamabad
A woman walks on a major highway as containers, which are to be used to block roads during a planned protest march, are seen in the background, in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Caren Firouz (PAKISTAN - Tags: POLITICS CIVIL UNREST)
A pedestrian walks past a container, which will be used to block roads during a planned protest march, in Islamabad
A pedestrian walks past a container, which will be used to block roads during a planned protest march, in Islamabad August 12, 2014. Pakistan's civilian government failed on Tuesday to persuade opposition leader Imran Khan to ditch plans to march on the capital in protest against alleged ballot rigging in last year's general election. REUTERS/Caren Firouz (PAKISTAN - Tags: POLITICS CIVIL UNREST)