Voters in Afghanistan have defied deadly attacks to cast ballots in large numbers in the nation's long-awaited parliamentary elections.
Several explosions targeted polling stations, with dozens of people killed or injured in scores of incidents across the country.
Voting will be extended amid delays, with some constituencies remaining open on Sunday.
A new biometric verification system has caused technical problems.
Violence had also marred election campaigning, with 10 candidates killed in the run-up to the polls. Both the Taliban and the Islamic State group had vowed to disrupt them.
More than 2,500 candidates, including many women, are vying for 250 seats in the legislative elections, which are being held more than three years late.
What are the levels of violence?
Polling day has seen dozens of incidents of violence, with scores of deaths and injuries reported:
- At least 15 people were killed in a suicide bombing in Kabul
- At least three people were killed and more than 30 others wounded in other incidents in Kabul, the AFP news agency reports
- According to the Associated Press, two police officers were wounded trying to defuse an improvised explosive device near a polling station in the north-west of the capital
- Three people were killed and more than 50 injured in the northern city of Kunduz, while another two people died in explosions in Nangarhar AFP reports
- Police officers were also ambushed in central Ghor province. At least four were killed in an explosion, although other reports put the death toll at 11
The defence ministry has deployed 70,000 members of the security forces to try to ensure the elections pass off peacefully.
But nearly a third of all polling stations were closed because of security concerns.
Security was not the only issue threatening the vote. Past elections have been marred by corruption and fraud, with cases of ballot box stuffing, multiple voting and voter intimidation all documented.
Why the delays on polling day?
Voting in Kandahar province had already been put off by a week after the assassination of a top police chief, Gen Abdul Raziq, on Thursday, in an attack claimed by Taliban militants. Polling in Ghazni province has also been delayed.
On Saturday, technical and organisational problems stopped voters from casting their ballots at a number of polling stations.
There have been technical hitches with Afghanistan's new biometric voter registration equipment and in the central province of Uruzgan, 15 men were reportedly arrested for trying to break biometric devices because of delays.
The Independent Election Commission says most stations opened their doors late because teachers employed to supervise the voting process failed to turn up on time, according to AFP news agency.
But the commission said turnout overall had been extremely good, Tolo reports.
There were long waits at many polling stations. One Kabul voter, Mustafa, told AFP: "The queue is getting longer. They have to register our votes quickly - we are afraid a bomber or a blast may hit us."
The results process will not be quick either. Preliminary results are not expected until 20 days after the election, on 10 November.
'We won't let Taliban win'
BBC's chief international correspondent, Lyse Doucet, in Kabul
It is an act of bravery to vote in Afghan elections. We went back to the same polling station we visited in 2014 and crowds were even larger this time. The queue of male voters kept getting longer.
There was a crush of voters in the women's section. So many Afghans told us, "We won't let the Taliban win."
But explosions are killing and injuring voters. Turnout will be low in the most insecure areas. Bad organisation is an enemy too. Afghans are angrily complaining about polling stations opening hours late, election material not showing up.
But many believe even holding this election is an achievement: to show that Afghan officials and security forces can do it, and to usher in a more legitimate parliament to replace a discredited assembly and try to move toward presidential elections next year and Taliban peace talks.
But if it is seen as a "bad election," it could be more consequential than not holding one at all.
Polling day - key numbers
Nearly nine million voters are entitled to cast their ballots in the vote.
Voting had been due to end at 11:30 GMT but the election commission now says it will continue until Sunday in centres which were unable to open on Saturday.
Only about 5,000 polling stations of the initially planned 7,000 are operational because of security concerns.
The Taliban have urged people to boycott what they call "fake" elections. And Islamic State militants in Afghanistan have followed suit.
Why do the elections matter?
Most Afghans are desperate for a better life, jobs, education and an end to the war with the Taliban.
For the country's foreign partners, seeing a flourishing democracy would be the return they're seeking after many years of investment, billions of dollars spent and thousands of lives lost in more than a decade of fighting.
Many candidates are young and well-educated. They are promising to help deliver change in the conflict-torn country.
But many Afghans have come to view all politicians as corrupt and ineffective, correspondents say.
The polls should have been held when the current assembly's five-year term ended in 2015. But the standoff after the disputed 2014 presidential election changed all that, bringing the country to the brink of civil war.
However, although parliament reviews and ratifies laws, real power lies with the presidency, and this election will be seen as a key test ahead of the all-important presidential elections due in April 2019.