KABUL: A suicide bomber killed at least 31 people and wounded dozens outside a voter registration centre in the Afghan capital Kabul on Sunday, the health ministry said, in the latest attack on election preparations.
The assaults underscore growing concerns about security in the lead-up to legislative elections scheduled for October 20, which are seen as a test-run for next year's presidential poll.
"It happened at the entrance gate of the centre. It was a suicide attack," Dawood Amin, city police chief, told AFP.
Health ministry spokesman Wahid Majroh said 31 people had been killed and 54 wounded. The higher toll could not be immediately confirmed, but a police official told AFP on condition of anonymity that at least 25 people had been killed and 70 wounded.
Earlier, interior ministry spokesman Najib Danish put the death toll at nine and 56 wounded. He could not immediately be reached for an update.
Afghan officials often give conflicting tolls in the wake of attacks and routinely understate the figures.
The centre in the heavily Shiite-populated neighbourhood in the west of the city was also being used by people to register for national identification certificates, which they need to sign up to vote.
Footage on Ariana TV showed pools of blood and shattered glass on the street.
Angry crowds shouted "Death to the government!" and "Death to the Taliban!" There was no immediate claim of responsibility.
The Taliban have denied they were involved.
A wounded man in a hospital bed wept as he told Ariana TV: "I don't know where my daughters are. God damn the attackers!" A witness to the attack named Akbar told Tolo TV: "Now we know the government cannot provide us security: we have to get armed and protect ourselves."
Photos posted on social media purportedly of the scene showed several bodies on the ground and a badly damaged two-storey building. Afghanistan began registering voters on April 14 for the long-delayed legislative elections.
Officials have acknowledged that security is a major concern as the Taliban and other militant groups control or contest large swathes of the country.
Afghan police and troops have been tasked with protecting polling centres, even as they struggle to get the upper hand against insurgents on the battlefield. Militants on Friday launched rockets at a voter registration centre in the northwestern province of Badghis.
At least one police officer was killed and another person was wounded, officials said, blaming the Taliban.
On Tuesday gunmen attacked a voter registration centre in the central province of Ghor, kidnapping three election workers and two policemen. Taliban militants released the five on Thursday.
Over the next two months, authorities hope to register up to 14 million adults at more than 7,000 polling centres for the parliamentary and district council elections.
Officials have been pushing people to register amid fears a low turnout will undermine the credibility of the polls.
The last major attack in Kabul was on March 21 when an Islamic State suicide bomber blew himself up in a crowd celebrating the Persian New Year holiday.
At least 33 people were killed and dozens more wounded in that blast, which also happened in a Shiite area of the city.
Since then a tense calm has permeated the Afghan capital as people brace for the Taliban's launch of its customary spring offensive.
The Taliban are under pressure to take up President Ashraf Ghani's peace offer made in February, but so far the group has given only a muted response. Some Western and Afghan officials expect 2018 to be a particularly bloody year.
General John Nicholson, the top US and NATO commander in Afghanistan, told Tolo TV last month that he expected the Taliban to carry out more suicide attacks this fighting season.