Iran has strongly denounced Thursday's assassination of three senior officials in Afghanistan’s Kandahar province, urging the conflicting sides to cease violence on the eve of parliamentary polls that have been delayed in the province by a week as a result of the assassinations.

Foreign Ministry spokesman Bahram Qassemi on Friday condemned the attack and offered sympathy to the Afghan government and nation as well as the bereaved families of the victims.

He highlighted the necessity of holding a national dialogue and putting an end to violence in Afghanistan, and expressed hope that the Afghan government and its opposition would seriously focus on establishment of peace and security ahead of the parliamentary votes that would start across the country - except for Kandahar - on Saturday.

“Iran strongly supports any initiative that guarantees the interests and benefits of the oppressed people of Afghanistan,” Qassemi noted.

On Thursday, at least three senior provincial officials in the southern province of Kandahar were killed by one of their own guards during a meeting to discuss security ahead of the vote. The Taliban claimed the attack, saying their target was US Gen. Scott Miller, the commander of US and NATO troops in Afghanistan, who was unharmed.

The terrorist attack came just two days before the parliamentary elections, which has been postponed until next week, according to Afghan officials.

Hafizullah Hashimi, spokesman of the Independent Election Commission, said the decision to delay the vote had been taken because the people of Kandahar were "morally not ready to vote" following the death of the commander, General Abdul Razeq, who was killed by the rogue bodyguard of another top official.

In the eight years since Afghanistan last held parliamentary elections, a resurgent Taliban have carried out near-daily attacks on security forces, seizing large swathes of the countryside and threatening major cities. A Daesh affiliate has launched a wave of bombings targeting the country's Shia minority, killing hundreds. Both groups have threatened to attack anyone taking part in the vote.

Despite the widespread pessimism, analysts and activists say the elections – which were delayed for three years because of insecurity – send an important message to the Taliban that no matter how unpopular the current government is, the political system is here to stay.

Security fears have forced the Independent Election Commission to close about 2,000 polling centers. It has cancelled the vote in 11 of the country's nearly 400 districts, as well as in the entire eastern province of Ghazni, where the Taliban control the countryside and laid siege to the provincial capital for five days in July. More than 50,000 security forces will be deployed to defend polling stations.

Wasima Badghisi, an operational deputy of the Independent Election Commission, says with 8.8 million registered voters, the turnout will reflect Afghans' confidence in the system.

"If 5 million voters turn out that will be very good," she said. "Those who vote, I feel they are very, very brave."