Pro-democracy protest groups in Hong Kong are urging people not to disrupt Sunday's local elections in the semi-autonomous Chinese territory.
They hope the polls will send a message to the government in Beijing after five months of political unrest.
The authorities have threatened to suspend voting if there is serious disruption at polling stations.
More than 400 councillors are due to be elected to Hong Kong's district council.
Pro-democracy campaigners hope they will be able to increase their representation on the council, which traditionally has some influence in choosing the city's chief executive.
Pro-Beijing candidates are urging voters to support them in order to express frustration at the upheaval caused by continuous clashes between protesters and police.
What's happening?
Polls opened at 7.30am local time on Sunday, with a record 4.1 million people registered to vote. Hong Kong has a population of 7.4 million.
More than 1,000 candidates are running for 452 district council seats which, for the first time, are all being contested. A further 27 seats are allocated to representatives of rural districts.
Currently, pro-Beijing parties hold the majority of these seats.
Why are these elections important?
District councils themselves have very little actual power, so usually these elections take place on a very local level.
But this election is different.
They're the first elections since anti-government protests started in June, so they will act as a litmus test, reflecting how much support there is for the current government.
"People in Hong Kong have begun to see this election as an additional way to articulate and express their views on the state of Hong Kong in general and the government of Carrie Lam," Kenneth Chan, associate professor at Hong Kong Baptist University, told news agency Reuters.
Then there's the issue of Hong Kong's chief executive.
Under Hong Kong's electoral system, 117 of the district councillors will also sit on the 1200-member committee that votes for the chief executive.
So a pro-democracy district win could translate eventually to a bigger share, and say, in who becomes the city's next leader.
Who is running?
There are some notable names running in the elections.
Pro-Beijing lawmaker Junius Ho - one of the most controversial politicians in the city - is among them.
Mr Ho was stabbed earlier this month by a man pretending to be a supporter.
The lawmaker has openly voiced his support for Hong Kong's police force on multiple occasions. He was in July filmed shaking hands with a group of men - suspected of being triad gangsters - who later assaulted pro-democracy protesters.
Jimmy Sham, a political activist who recently rose to prominence as the leader of the Civil Human Rights Front - a campaign group responsible for organising some of the mass protest marches - is running for the first time.
Mr Sham has also been attacked twice, once apparently with hammers. Photographs showed him lying on the street covered in blood.
Who isn't running is also notable. Pro-democracy activist Joshua Wong was barred from running in the elections, a move he referred to as "political screening".
- BBC