"Ahmed was going in a convoy of eight to 10 vehicles on a campaign when the blast occurred, killing two people," Waqif Khan, Swat's senior police official, said.
The latest deaths will increase fears of security in the run-up to the election on February 18 for which tens of thousands of extra military troops will be deployed nationwide.
Two suicide bomb attacks on election rallies in different parts of northwest Pakistan have killed at least 22 people and wounded more than 30 in the past week alone.
The election was originally scheduled for January 5 but was postponed to next Monday after Benazir Bhutto, a former prime minister and opposition leader, was assassinated on December 27.
The government has blamed Baitullah Mehsud, a Pakistani Taliban leader based on the Afghan border who it says has links to al-Qaeda, for the attack on Bhutto and many others across the country.
But Mehsud's spokesman, Maulvi Omar, claimed to the Reuters news agency on Wednesday that the Pakistani Taliban group had decided not to target the election and that their men would not be involved in any attack before or on election day.
Meanwhile poilice investigating Bhutto’s assasination claimed they have made a “breakthrough” when two men arrested last week allegedly confessed to giving a pistol and vest with explosives to the man suspected of the killing.
"They have confessed that they gave a suicide jacket and a pistol to the bomber," Deputy Inspector General Chaudhry Abdul Majeed told reporters.
"It's a major breakthrough. Their confession is a major piece of evidence in the case," he said.
Majeed, who is heading the investigation, said the confessions were made by two men arrested in Rawalpindi last week and identified as Hasnain Gul and Rifaqat.
He said they had confessed during interrogation that "they facilitated and harboured [the bomber] Saeed alias Bilal."
Majeed said the police were still investigating possible links between the militants and Mehsud.
However Bhutto's aides have cast doubt over the government investigation of the assassination of the two-time prime minister.
There is also uncertainty over whether Bhutto was killed by a bullet or by a concussive head injury caused by the detonation of the bomb after the assassin had fired at her.
|Zardari and the PPP are leading in polls |
ahead of the election [AFP]
Aides insist Bhutto was shot before the blast, and want a United Nations investigation to find her killer - a demand the government has rejected.
Meanwhile Asif Ali Zardari, Bhutto's widower, has said he would form a "government of national consensus" if her Pakistan People's party (PPP) wins the elections.
His comments appeared to leave the door open for a power-sharing agreement with either Nawaz Sharif, another former prime minister, or even the party that backs Pervez Musharraf, the current president.
"I think a dilemma that the military government has put Pakistan in today leaves us no choice but to try and get together with all the political forces," Zardari told the AFP news agency in an interview at his home in Lahore.
"I have already taken a position politically that we shall make a government of national consensus with everybody," he said.
Zardari is leading the PPP until his son with Bhutto completes his education.
Zardari held talks with Sharif in Lahore on Tuesday night at which the two leaders said they had discussed a possible coalition, after surveys showed both of their parties were ahead of Musharraf's party.
However Musharraf's ruling Muslim League-Q party has also expressed confidence on Wednesday that it will form a new government.
A survey released on Monday by the US government-funded International Republican Institute showed overwhelming support for the opposition and predicted the ruling party would fare poorly.
The survey said half the Pakistanis polled planned to vote for the PPP and 22 per cent backed Sharif's Muslim League-N.