Chinese police briefly detained two organisers of an independent film festival which was shut down on its opening day, an associate said Sunday, amid a clampdown on free expression.

Festival officials Li Xianting and Wang Hongwei were taken away Saturday by police who closed down the 11th Beijing Independent Film Festival, said Wang Shu, who works with the Li Xianting Film Fund behind the event.

"They came back last night, but I haven't seen them yet and don't have details on the situation" Wang Shu told AFP.

She added it was "inconvenient" to divulge too many details to media.

Li, a film critic, is the founder of the Li Xianting Film Fund, while Wang Hongwei is the festival's artistic director.

Police had prevented film industry workers and the audience from attending the festival, Wang Shu said on Saturday, saying it was "forced to close".

The festival has regularly run afoul of the authorities. Its opening day last year was disrupted although organisers continued the event in defiance.

Heavy security also turned out in 2012, when state media reported that the event was interrupted by a power cut.

Sources told AFP that authorities had put heavy pressure on organisers to cancel this year's festival in the days leading up to it.

AFP was also told that the films to be screened at the festival were not "sensitive" in terms of being anti-government.

Local police told AFP Saturday that they were not aware of the festival.

Chinese authorities keep a tight grip on information, with the media controlled by the government and online social networks subject to heavy censorship.

Hundreds of Internet bloggers and journalists have since last year been rounded up in a government-backed campaign against "Internet rumours".

The clampdown appears to be part of a concerted effort by the ruling Communist Party, which maintains an iron grip on power, to rein in criticism.

China this year has jailed around 10 members of the New Citizens Movement, a loose network whose members held peaceful protests in Beijing and other cities last year calling for officials to disclose their assets.

A founder of the movement, legal scholar Xu Zhiyong, was jailed for four years in January.

Under President Xi Jinping, who assumed party leadership in 2012, it has repeatedly vowed to combat rampant graft in the face of public anger over the issue.

But the party has cracked down on activists pursuing the same goals, seeing independently-organised groups as a challenge to its grip on power.

The arts have been no exception.

Guo Jian, a Chinese-Australian artist and former Tiananmen Square protester, was detained in June after making an artwork about the 1989 crackdown ahead of its 25th anniversary and was ordered deported from China.

Tiananmen is a particular sore spot for authorities who do their utmost to wipe even the slightest reference to the crackdown from books, television and the Internet.