Former Pakistani Prime Minister Benazir Bhutto joins in special prayers for the victims of the Karachi attack, as mourners gather around the country. Hundreds of people and Bhutto's supporters gathered in the cities of Karachi and Lahore in Pakistan on Sunday (October 21) to offer special prayers for the victims of a suicide attack last week that killed 139 people. At least 139 people were killed in Friday's attack on opposition leader Benazir Bhutto during her homecoming parade in Karachi and 325 were wounded. On Saturday (October 20), a car bomb killed four people in the southwestern province of Baluchistan. A countrywide day of mourning was being held on Sunday for the victims of the Karachi attack. "Pakistan People's Party had made a call for a three-day mourning period. Today is the last day. Special prayers at district levels have been offered throughout the country," said Mian Raza Rabbani, a central leader of Bhutto's Pakistan People's Party and leader of the opposition in senate, the upper house of Pakistani parliament. Bhutto visited bomb blast survivors being treated at the government's Jinnah hospital in Karachi. She also gave special prayers for the victims of last week's suicide bombing. Downcast mothers, widows and children of several victims sat among scores of female party workers as together they prayed for those killed in the blasts. "I appeal to every mother here to bring up their children in such a way that they grow up to bring a good name to our country and our religion. For the progress of this country, I ask you to teach your sons never to attack innocent people," Bhutto told the gathering of women at her seaside house. "A martyr lives on ... the death of a martyr is actually life. Those who are martyred never die," said Rehana Bibi, as Bhutto cradled the two young daughters of Bibi's 29-year-old brother Shafique who had lost his life in the tragedy. On Saturday (October 20), police released a photograph of the suspected suicide bomber and offered a reward for anyone who could identify him. They said they had several leads and were making progress in the investigation but they declined to give details. The threat of violence looming over Pakistani politics adds to an atmosphere of distrust but is unlikely to derail tentative steps on a transition to civilian rule, analysts said. The government has said the violence would not affect plans for a general election although campaigning might have to be curtailed. Bhutto said a code of conduct would be prepared in consultation with other political parties in view of the deteriorating security situation. Military President Pervez Musharraf and former Prime Minister Bhutto share a determination to tackle al Qaeda and allied militants, and nuclear-armed Pakistan's Western allies have been quietly encouraging the two to cooperate. But suspicion in Bhutto's camp that rogue security elements are egging on militant bombers might upset reconciliation efforts that could see her and Musharraf -- who has also survived suicide bomb attacks -- sharing power after a January poll. The government suspects al Qaeda-linked militants based on the Afghan border were responsible for the suicide bombing. They have carried out a string of similar attacks on the security forces and other targets, killing hundreds of people in recent months. Bhutto has alluded to enemies in the Pakistani establishment spreading militancy and plotting against her although she stressed she was not blaming the government for the attack. Musharraf won a disputed presidential election on October 6 although the Supreme Court has yet to ratify his victory while still army chief. He has promised to quit the army before being sworn in for a new term by mid-November. The government said the Karachi violence would not affect the general election but officials have indicated campaigning could be restricted because of the threat of violence. Despite that likelihood, changes were underway that will see the military, which has ruled for more than half of the 60 years since Pakistan's creation, edging out of politics. But analysts said for the election to be seen as fair, the government had to allow the participation of another former prime minister, Nawaz Sharif, whom Musharraf ousted in 1999 and later exiled. Sharif tried to return last month but was deported. Musharraf cobbled together his powerbase from Sharif's party and his return to politics could trigger defections from Musharraf.