Media playback is unsupported on your device Media caption Scuffles broke out between protesters and police

Police and pro-democracy protesters have clashed in a battle for territory in the Hong Kong district of Mong Kok.

For the fourth night in a row, police charged after demonstrators breached their barriers, sparking scuffles that caused minor injuries on both sides.

The protesters are angry at China's rulers for limiting their choice of leader in the next election in 2017.

Leaders on both sides have called for calm, and confirmed that talks will take place on Tuesday.

Protesters, most of them students, accuse Hong Kong's current leader, CY Leung, of failing to stand up to the Chinese Communist Party.

Image copyright EPA Image caption In the early hours of Sunday, police charged at protesters in Mong Kok

Image copyright AP Image caption It was unclear what sparked the charge, with some reports saying protesters had tried to breach barricades

Protests erupted last month and have been going on intermittently around government buildings and the business district, and in Mong Kok, a residential and shopping area in Kowloon.

On Friday morning, police had all but cleared the Mong Kok site and protesters' numbers had substantially dwindled elsewhere.

However, clashes resumed later that day as thousands of protesters launched a sustained effort to reoccupy a busy road junction in Mong Kok, and 26 people were arrested.

Image copyright AP Image caption Many of the protesters were brandishing umbrellas, one of the features of the demonstration

Image copyright EPA Image caption The demonstrators flooded back into Mong Kok late on Friday

At about midnight on Saturday (16:00 GMT), police charged protesters, beating them with batons and deploying pepper spray.

A stand-off resumed shortly afterwards with neither side having gained any ground.

Media playback is unsupported on your device Media caption The government confirms talks with students on Tuesday despite protesters retaking Mong Kok

Carrie Lam, CY Leung's deputy, said Tuesday's talks would be focused on constitutional reform. Both sides will send five representatives to the negotiations, which will be broadcast live on television.

Hong Kong timeline

1997 : UK gives Hong Kong back to China under a 1984 agreement giving it "a high degree of autonomy" for 50 years

: UK gives Hong Kong back to China under a 1984 agreement giving it "a high degree of autonomy" for 50 years 2004 : China says it must approve any changes to Hong Kong's election laws

: China says it must approve any changes to Hong Kong's election laws June-July 2014 : Pro-democracy activists hold unofficial referendum on political reform; both sides hold large rallies

: Pro-democracy activists hold unofficial referendum on political reform; both sides hold large rallies 31 August 2014 : China says it will allow direct elections in 2017 but will pre-approve candidates

: China says it will allow direct elections in 2017 but will pre-approve candidates 22 September 2014: Student groups launch a week-long boycott of classes

Student groups launch a week-long boycott of classes 28 September 2014: Occupy Central and student protests join forces for mass protest

Hong Kong's democracy controversy