Hong Kong police seized a second statue dedicated to victims of the 1989 Tiananmen Square crackdown in what critics called an attack on freedom of expression in the semi-autonomous Chinese territory.

The Chinese military's suppression of pro-democracy student protests in June 1989, which killed at least hundreds, is off-limits on the mainland, but it is openly mourned and criticised in Hong Kong, a former British colony that is guaranteed Western-style civil liberties.

But days before the crackdown's 21st anniversary, Hong Kong democracy activists accused authorities of taking a less tolerant approach this year.

On Saturday, Hong Kong police confiscated a large statue and a carving erected in memory of the Tiananmen victims on the grounds that activists did not have a licence to display them. They also arrested 13 people who tried to protect the two pieces.

Defiant activists paraded a second statue - a smaller version of the "Goddess of Democracy" statue seized on Saturday - during a protest yesterday, and left it by a popular shopping mall late in the day.

Hong Kong police took it about an hour later, said Lee Cheuk-yan, a pro-democracy politician who was guarding the statue. Mr Lee, who was also arrested on Saturday, was detained again yesterday along with a fellow activist.

"This is an escalation in political persecution. They can't even tolerate a Goddess of Democracy statue. What kind of government is this? What kind of Hong Kong is this?" Mr Lee said.

The opposition politician was not immediately charged and was freed on bail after two hours.

Police said they removed the second statue because it also wasn't licensed. The two activists were arrested on suspicion of interfering with police work, they said.

A Hong Kong Cabinet official declined to comment on the seized statues and arrests, but said the government had no intention of banning the territory's annual candlelight vigil in honour of Tiananmen victims scheduled for Friday.

The vigil typically draws tens of thousands of people.

Secretary for constitutional and mainland affairs Stephen Lam said the gathering had been held every year, and added: "This year is no exception."

As part of its special semi-autonomous status under Chinese rule, Hong Kong is supposed to enjoy Western-style freedoms that are typically denied in the mainland, but critics say the local government is gradually curbing those freedoms under pressure from Beijing.