Eight people were arrested in Hong Kong late Sunday after scuffles broke out between police and demonstrators during a pro-democracy protest, as tensions rise following the launch of a controversial election roadmap.

Television footage showed clashes in the shopping district of Mong Kok as police officers wielded batons and used pepper spray to disperse dozens of protesters who were trying to block traffic on a major road.

Five of those arrested were accused of assaulting officers, a spokesman said.

The government's contentious leadership election roadmap, which was released on Wednesday, has prompted several protests.

The plan conforms to a ruling from Beijing in August that all candidates should be vetted before a public vote in 2017, which sparked mass protests towards the end of last year.

Critics have slammed Beijing's framework for the vote as "fake democracy".

At the height of last year's rallies, thousands occupied three major thoroughfares, including one in Mong Kok -- a flashpoint that saw some of the most serious outbreaks of violence.

Police said that the most recent scuffles broke out late on Sunday at around midnight, and confirmed pepper spray was used.

"One tried to snatch away an officer's baton, and used his leg to attack the officer," the spokesman said.

"Another refused to go back to the pedestrian walkway from the road and stopped police from making arrests."

Protesters were angry with officers after they took away two demonstrators who had been arguing with a government supporter, according to local media.

Dozens of protesters then briefly blocked a road and stood in front of a police van.

Britain handed Hong Kong over to China in 1997 under a joint declaration which guaranteed political, social and economic freedoms not enjoyed on the Chinese mainland.

The semi-autonomous city is governed under that "one country, two systems" deal, but there are fears that freedoms are being eroded under Beijing's influence.

Student leaders have warned of increased civil disobedience following the announcement of the government's election plan, and have mooted the idea of occupying the Legislative Council when the electoral reform bill is debated later this year.

On Saturday, scuffles broke out in residential Kennedy Town when protesters heckled senior officials on a "bus parade" to promote the government plan.

Police said a total of 11 protesters were arrested over the weekend.