BEIJING (AFP) — China issued new rules on Thursday aiming to crack down on "harmful" political or religious online videos, two weeks after footage of police allegedly beating Tibetan monks circulated on the Web.

The rules specifically ban online clips that harm national stability, "instigate hatred between ethnic groups" or "maliciously disparage" the nation's police or armed forces, a notice on the government's website said.

The India-based government of the exiled Tibetan spiritual leader, the Dalai Lama, last month released footage allegedly showing brutality by Chinese security forces in Tibet.

The video appeared to show Tibetans, some in monks' robes, being shackled and beaten by police during anti-Chinese protests across the Tibetan plateau in March last year.

After the clips appeared online, access to video-sharing site YouTube was unavailable in China. A foreign ministry spokesman has refused to confirm whether the government blocked the site.

Chinese authorities have a history of blocking websites they deem politically unacceptable or offensive, and their censoring of the Internet has created a so-called "Great Firewall of China".

The tightened restrictions issued by the State Administration of Radio, Film and Television, were intended to "enhance the building and management of an Internet culture, disseminate the advanced culture of socialism, and reject vulgarity," the government notice said.

The rules also took aim at sexual and religious content.

They ban the posting of videos that "advocate evil cults and superstitions," a phrase China often uses to refer to the banned Falungong spiritual sect, which the government views as a potential threat to its authority.

Also prohibited is the posting and downloading of movies and television shows that have not received permission to be shown in China, including foreign films.

Chinese media reports said this could curb what is now a widespread practice of illegally downloading such entertainment.

"From today on, you will never be allowed to download and watch a foreign movie, television show, or cartoon that has not yet been in cinemas or broadcast on television," said an article in the Beijing Evening News.

However it added that websites were awaiting more specifics on the implementation of the policy before assessing the impact.

China grants approval for only 20 foreign films to be screened in China each year and often first requires that objectionable content be deleted.

In 2006 it ordered that scenes showing laundry drying on balconies in Shanghai be deleted before "Mission Impossible III", partly filmed in the city, could be screened, state media said at the time.

China has in recent years tried to rein in an explosion of online video content, which is often the only way ordinary citizens can view videos of such things as anti-government protests that would never be aired on the country's tightly controlled state television.

In January last year, China ruled that only state-owned or state-controlled entities could operate websites that post audio-visual material. Following an outcry, it later amended that to include private firms in good standing before the new rules.

China has the largest online population in the world -- nearly 300 million at the end of 2008 according to Chinese figures.