A suicide bomber blew himself up in the Afghan capital on Saturday, killing at least 15 people as voting concluded in parliamentary elections overshadowed by the threat of violence and long delays at polling stations.

There was no immediate claim of responsibility for the bombing, which appeared to have been the most serious of a day marked by a series of smaller-scale attacks that caused dozens of casualties across the country.

Voting should have been concluded by the time the suicide bomber struck a polling station in the north of Kabul, killing 10 civilians and five police, but polling stations were kept open longer than normal to cope with large numbers of people who had been unable to cast ballots.

Turnout was higher than expected, with long lines forming outside polling centres in the main cities, but many voters were forced to endure extended waits because of technical and organisational problems.

"People's enthusiasm and participation despite threats, intimidation and attacks by militants must be lauded today," said one senior international security official, who added: "The electioneering process will require close scrutiny as it is clear that there were multiple failures."

Untested biometric voter-registration equipment, rushed in at the last minute to counter voter fraud, caused particular problems. The Transparent Election Foundation of Afghanistan, a civil action group, said the devices suffered malfunctions in more than 40 per cent of polling centres.

"The biggest problem is with the biometric machines, there are some sites where they're not working and a lot of voters have been discouraged and have gone home," said Nasibullah Sayedi, a voter in the western city of Herat.

The Independent Election Commission (IEC), the body overseeing the ballot, said voting hours would be extended in some centres to cope with demand and some polling stations, which had not opened at all, would be open on Sunday.

In the days leading to the vote, Taleban militants issued a series of statements telling people not to take part in what they consider a foreign-imposed process and warning election centres may be attacked. Security officials said there were more than 120 hand grenade or improvised explosives attacks but they said many of these did not target voting centres but were aimed nearby, apparently with the aim of frightening voters away rather than causing casualties.

Afghanistan's political scene is still tainted by the aftermath of a disputed presidential vote in 2014 that forced the two main rival groupings to form an unstable partnership. Both sides were accused of massive electoral cheating.

But high turnout, at least in the major cities, reflected strong support for the process in the face of threats from militant attacks and widespread disillusion with a corrupt political class.

"I want candidates to serve the country and hear the voices of the disabled and the poor," said Abdullah, a wheelchair-bound voter in Herat. "People ask what difference one person's vote will make but I say, if a million disabled people come out to vote, don't you think that will make a difference?"

However numerous allegations of voter fraud made before election have presented a challenge to the legitimacy of the process, seen by Afghanistan's international partners as a vital step ahead of more important presidential elections next year.
Timeline of election-day incidents

7.20am-Tens of thousands of Afghan forces have fanned out across the country as voting began in parliamentary elections

9.30am-A small explosion has frightened voters who had lined up at a polling station in the Qarabagh neighbourhood

10.10am-A Kabul police official says a second small explosion has been reported just hours after polls began

10.45am-Two attacks in northern Afghanistan have wounded two women

12.05 pm-Two police were wounded when they tried to defuse an improvised explosive device found near a polling station

3.20pm-Two people died and 22 were injured when insurgents fired several rockets and mortars at a variety of targets in the Baghlani Markazi district

5.10pm-The closing of polls amid reports of high turnout

From: Khaleejtimes