Hong Kong police have clashed with pro-democracy activists trying to surround government offices, in some of the worst unrest in two months of protests.

Police charged on the protesters, using batons and pepper spray

Protesters fought police armed with pepper spray and batons on roads around the camp in the Admiralty district.

Police say 40 people have been arrested and a number of officers were injured.

The protesters want the people of Hong Kong to be allowed to choose their leaders in the 2017 elections without interference from Beijing.

The Chinese government has said it will allow universal suffrage, but will screen candidates for the chief executive post in advance.

Last week police and court bailiffs removed one of the major protest camps in the Mong Kok commercial district.

The unrest flared overnight, after student leaders of the protest movement called on supporters to converge on the offices of Chief Executive CY Leung on Lung Wo Road.

The road is a short distance away from Connaught Road in Admiralty, the major road protesters have been occupying for two months.

Protesters, many wearing hard hats and carrying umbrellas - the symbol of their movement - moved into the area, throwing bottles, helmets and umbrellas towards police.

Many activists chanted: "I want true democracy!"

"I urge everyone to stay here until the morning to keep surrounding the government headquarters. Let's stop the government from functioning tomorrow," a protester in a black T-shirt shouted, Reuters news agency reported.

Student leaders have called for an escalation of the protests

Police ordered them to retreat, then charged protesters, eventually forcing them out of the area.

"The action was aimed at paralysing the government's operation,'' student leader Alex Chow was quoted by the Associated Press as saying.

"The government has been stalling... and we believe we need to focus pressure on the government headquarters, the symbol of the government's power.''

On Monday government offices were shut and staff were told to stay home. But the roads outside the government site were clear of protesters and open for traffic.

The atmosphere remained tense at Connaught Road where hundreds of protesters are still occupying the area amid a police presence.

Last week more than 100 people - including some key protest leaders - were arrested as the Mong Kok camp, across the harbour from Admiralty, was dismantled.

The latest clashes come after China said it would not allow a UK parliamentary committee to enter Hong Kong as part of an inquiry into British relations with its former colony.

Source: BBC