Pro-democracy protesters have clashed with police in Hong Kong for the first time in more than two weeks as pressure grows on demonstrators to abandon more than a month and a half of street occupations.
Wednesday's scuffles lasted for about four hours in the busy Mong Kok neighbourhood.
Police said they attempted to arrest a man who was shining his mobile-phone light into officers' eyes, and demonstrators responded by surging at police lines.
The two sides ended up in a tense standoff, with several protesters taunting police.
At about 2:30am, protesters charged again at police lines and flooded into a street. Officers responded with pepper spray and pushed the crowd back into their camp.
Police said they arrested three people in the confrontations, which left at least one protester bleeding from the head.
Several demonstrators arrived in Mong Kok wearing masks with the grinning likeness of Guy Fawkes, a co-conspirator in a plot to blow up the English Parliament building in 1605.
Young protesters worldwide have taken up wearing the mask at demonstrations since it was featured in the 2006 film V for Vendetta.
Thousands of people remain camped out on Hong Kong's streets demanding open nominations in elections for the city's leader.
The protests erupted in late September after Beijing ruled that a China-friendly committee would screen the candidates.