Pakistanis gather around the body of Sadiq Zaman Khattak, a candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Arshad)

Pakistanis gather around the body of Sadiq Zaman Khattak, a candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Arshad)

Pakistanis mourn for the death of Sadiq Zaman Khattak, candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Masroor)

Pakistanis mourn for the death of Sadiq Zaman Khattak, candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Masroor)

Pakistanis mourn for the death of Sadiq Zaman Khattak, candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Masroor)

Pakistanis gather around the body of Sadiq Zaman Khattak, a candidate for a National Assembly seat of the ethnic Pashtoon "Awami National Party' (ANP), who was shot dead by gunmen on May 3, 2013, in the Pakistani port city of Karachi in a latest pre-election targeted attack. (Xinhua/Arshad)