Media playback is unsupported on your device Media caption Police moved in to the Mong Kok camp late on Tuesday night

Two leading student activists are among scores of people arrested in Hong Kong in a crackdown on the two-month long pro-democracy street protests.

Authorities began demolishing one of the largest camps, in the Mong Kok commercial district, on Tuesday.

The operation began peacefully but scuffles broke out overnight and in the morning, during which Joshua Wong and Lester Shum were held for contempt.

Police say streets around Nathan Road are clear for the first time in weeks.

Some activists have said they will regroup elsewhere, vowing to continue their demands for a free choice of leader for Hong Kong's chief executive elections in 2017.

Other protest camps remain in the government district and the Causeway Bay shopping area.

Analysis: John Sudworth, BBC News, Shanghai

There have been attempts to clear Hong Kong's streets before, notably of course, right at the beginning of the protests. Video footage of the protesters defending themselves with umbrellas from the pepper spray became the defining image and only served to give the movement massive momentum.

Now though, the authorities are taking a more careful approach. Recent clearance efforts, including those over the past two days in the Mong Kok district, have been to enforce the court injunctions, won by businesses including the city's taxi drivers, angered over the effect on their businesses.

They also come at a time when the protesters are weary after two solid months of sit-ins, their numbers dwindling, and not long after the world spotlight has left China following the Apec Summit. Scenes of Hong Kong chaos might not have played well with the world leaders meeting in Beijing.

But with Mong Kok cleared, two other sites remain, including the main protest site in the heart of the financial district. Further court injunctions or not, that remains a much tougher proposition.

The authorities have moved in on Mong Kok after local businesses secured court injunctions against the disruption to their businesses.

Image copyright EPA Image caption Police formed a human barrier (top) as they moved in on the Nathan Road protest site on Wednesday

Image copyright AP Image caption The bailiffs were helped by volunteers wearing white and red outfits, who occasionally clashed with protesters

Image copyright Reuters Image caption Dozens of protesters who refused to leave were detained

Image copyright AFP Image caption Workers quickly moved in to hose down the roads after they were cleared

Early on Tuesday, court bailiffs backed by police removed a section of the camp at the junction between Nathan Road and Argyle Street.

Many protesters packed up and moved elsewhere but scores resisted, leading to arrests for contempt of court and obstructing police officers.

Then late at night on Tuesday and in the early hours of Wednesday, bailiffs and police - some carrying pepper spray and batons - also began clearing camps on Nathan Road, a major thoroughfare in Kowloon.

The court injunction was read out before bailiffs and workers - some wearing T-shirts that read "I love HK" - began dismantling barricades made of wooden pallets and other materials.

Police officers wearing helmets tore down tents and canopies. Other officers were standing by with backpack pepper sprayers, local media reported.

Image copyright AP Image caption Protesters cleared structures at the Mong Kok camp including an altar for Chinese god Guan Yu

Image copyright AFP Image caption Pepper spray was used to disperse crowds on Tuesday night

Image copyright Reuters Image caption Police arrested people on charges including possessing offensive weapons and obstructing officers

The Hong Kong Federation of Students said its leading activist Lester Shum was detained, along with Joshua Wong of the Scholarism movement and a number of other key protest figures.

It is Mr Wong's second arrest in recent months, after he was detained in September at the start of the protests.

Other arrests were for alleged offences including assaulting police, possessing offensive weapons and obstructing officers.

Mr Wong, from the Scholarism group, had earlier said the court orders were being used as an excuse to remove activists, according to the South China Morning Post.

Hong Kong democracy timeline

1984: Britain and China sign an agreement where Hong Kong is guaranteed "a high degree of autonomy, except in foreign and defence affairs" for 50 years following the handover in 1997.

June-July 2014: Pro-democracy activists hold an unofficial referendum on political reform and a large rally. This is followed by protests by pro-Beijing activists.

31 August 2014: China says it will allow direct elections in 2017, but voters will only be able to choose from a list of pre-approved candidates. Activists stage protests.

22 September 2014: Student groups launch a week-long boycott of classes in protest.

28 September 2014: Occupy Central and student protests join forces and take over central Hong Kong.

October 2014: Chief Executive CY Leung refuses demands for his resignation. Discussions between government and student leaders go nowhere. High court begins granting injunctions to clear protest sites.

15 November 2014: Student leaders' attempt to travel to Beijing fails.

18 November 2014: Bailiffs move in to clear a portion of the Admiralty protest site.

2017: Direct elections for chief executive due to take place

Q&A: Hong Kong's democracy controversy

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