Supporters of the Muttahida Qaumi Movement (MQM) participate in an election campaign rally in southern Pakistani port city of Karachi on May 6, 2013. (Xinhua/Masroor)

Supporters of the Muttahida Qaumi Movement (MQM) participate in an election campaign rally in southern Pakistani port city of Karachi on May 6, 2013. (Xinhua/Masroor)

Supporters of the Muttahida Qaumi Movement (MQM) participate in an election campaign rally in southern Pakistani port city of Karachi on May 6, 2013. (Xinhua/Masroor)

Supporters of Imran Khan, cricket legend and chairman of Pakistan Tehreek-e-Insaf (PTI) or Movement for Justice, waves party flags in an election campaign rally in central Pakistan's Multan on May 6, 2013. Pakistan will elect its new government for the next five years in polls on May 11. (Xinhua/Stringer)

Supporters of Imran Khan, cricket legend and chairman of Pakistan Tehreek-e-Insaf (PTI) or Movement for Justice, waves party flags in an election campaign rally in central Pakistan's Multan on May 6, 2013. Pakistan will elect its new government for the next five years in polls on May 11. (Xinhua/Stringer)

Pakistani cricket legend and chairman of Pakistan Tehreek-e-Insaf (PTI) or Movement for Justice, Imran Khan (C) addresses an election campaign rally in central Pakistan's Multan on May 6, 2013. Pakistan will elect its new government for the next five years in polls on May 11. (Xinhua/Stringer)