Rush-hour traffic streamed through the heart of Hong Kong for the first time in more than two months Friday after police cleared the city's main pro-democracy protest camp with mass arrests -- but activists vowed that their struggle would go on.

The east-west artery through the city's business district had been blocked since September by the sprawling protest site in a campaign that demonstrators say has changed the city's vexed relationship with Beijing forever, and which has polarised public opinion in the city.

Police swept through the Admiralty site Thursday, clearing the multi-lane highway and arresting more than 200 protesters.

The demonstrators are calling for fully free elections for the city's leader in 2017, but Beijing has insisted a loyalist committee vet the candidates, which protesters say would ensure the selection of a pro-China stooge.

Demonstrators feel their lengthy occupation has put the democracy movement on the map with Beijing and the local administration, after it brought parts of the city to a standstill and saw tens of thousands on the street at its height.

But it has achieved no political concessions from either Hong Kong's leaders or Beijing, who both branded the protests "illegal".

Despite that, protest leaders said they would continue to push for reform.

"If we fight a long war we definitely do not have the... resources the government has," said teenage student leader Joshua Wong Thursday.

Instead the movement needed to galvanise the support of young voters, many of whom engaged with politics for the first time during the mass protests.

"If we win the support of the young people regarding democracy... there is a greater chance to achieve universal suffrage."

Leader of the Occupy Central campaign group, Benny Tai, warned of more action to come.

"If the problem of political reform is not handled appropriately I believe the next phase there will be new resistance actions. Would it be long-term occupation of streets? Maybe not," he said.

Tai handed himself in to police last week in a symbolic bid to get the protests off the street in the wake of violent clashes, only to be turned away without being charged or arrested.

- Coherent voice -

Analysts said the pro-democracy movement -- from students to legislators -- would have to become more coherent if it were to achieve any political concessions.

"They need to pull together to create a viable coalition of stakeholders," said political analyst Willy Lam of the Chinese University of Hong Kong.

"They need to act together to lobby and negotiate with the (Hong Kong) administration and Beijing. That would also give the Hong Kong people the impression that they speak with one voice and are much more organised," said Lam.

Public support for the movement waned as the weeks of protests wore on and the campaign splintered in different directions.

Some in Admiralty Friday expressed their support for the police clearance action.

"I think it was correct because they broke the law," said one 46-year-old civil servant who gave his name as George.

But others expressed disappointment and the need for the movement to continue.

"I am so depressed it's gone," said Kim Lo, 34, who works in property.

"I think now we have to sit down and think what we want. We need to spread the message, to help the seed grow. I don't think we should go back on the streets yet."