Protesters have taken to the streets in cities throughout Pakistan to rally against severe electricity shortages.

In Punjab province, police clashed with demonstrators who threw stones and tried to block roads in Lahore and Gujranwala on Tuesday.

Residents of many of Pakistan's urban areas complain of receiving no electricity for up to 20 hours a day. The power shortages impact medical facilities, where doctors struggle to treat patients. Businesses have also been severely affected.

Pakistan's main opposition leader and former prime minister Nawaz Sharif on Tuesday accused the federal government of mismanaging the power supply and not doing enough to deal with the problem.

Pakistani Prime Minister Yousuf Raza Gilani has sought to deflect blame away from his government, instead calling on the United States to provide energy assistance.

Pakistani leaders partially blame electric companies' lack of funds for the power shortages.