Japanese newspapers warned Wednesday that freedom of expression was at stake after cinemas pulled a documentary about a Tokyo shrine honouring war dead amid pressure from nationalists.

"Freedom of expression is under threat," the Asahi newspaper said in an editorial, following the decision by four more Japanese cinemas to cancel planned screenings of "Yasukuni", by Chinese director Li Ying.

"Japan experienced more than enough, more than 60 years ago, how suffocating and unhealthy a society is when people cannot say things or express themselves freely," it added.

Japan's top selling daily, Yomiuri Shimbun, ran an editorial headlined: "Freedom of expression must be protected."

"Expressed views should be afforded every respect, no matter what political message they might be espousing, whether left-wing or right-wing," it said.

The Tokyo Shimbun, a regional daily, added: "Excessive 'self-censorship' has trampled on freedom of expression."

The film, which received an art's grant from Japan's government, looks at the controversy surrounding the Yasukuni shrine, which was built in 1869 and now honours 2.5 million war dead -- including convicted war criminals from World War II.

The site has become a rallying point for Japan's far right, but in much of Asia, it is seen as a symbol of Japan's past militarism.

The documentary, which was originally scheduled to premier on April 12, looks unlikely to be shown at all in Japan after all the cinemas in Tokyo that were planning to show it cancelled amid pressure from right-wingers.

The conservative Sankei newspaper said the cancellation was "disappointing" because people had lost a chance to discuss the documentary.

Cinema operators said they feared inconvenience to neighbouring businesses and the safety of their staff after noisy protests by nationalists, who argue that the film contains anti-Japanese elements and should not be shown in Japan.

A number of Japanese lawmakers had requested a private advance viewing of the film, which critics said was tantamount to censorship.