Beijing has mobilised 850,000 residents to patrol the city to ensure security ahead of a huge military parade commemorating victory over Japan in World War II, state media reported.

The "volunteers" from "all walks of life" have been trained and will be sent to "every street, every alley" as well as stores and markets, the official Xinhua news agency said late Wednesday, citing a Beijing police spokesman.

They will look for signs of "security hazards" and report them to police, it added.

The Chinese government often uses huge amounts of manpower to strengthen security during major events, such as the 2008 Beijing Olympics and the following year's 60th anniversary of the founding of Communist China in 1949.

A series of other measures have also been taken for the parade on September 3, which will mark the 70th anniversary of victory over Japanese forces as well as the broader defeat of the Axis powers in World War II.

Communist China generally shies away from the vast annual demonstrations of military might that were a hallmark of the Soviet Union, normally holding such events once a decade to mark the foundation of the People's Republic.

But Beijing is becoming increasingly assertive in the region and regularly accuses Tokyo of failing to show sufficient contrition for Japan's 20th-century invasion of China.

Other than Russia's Vladimir Putin few major foreign leaders have said they will join, although South Korean officials said Thursday that President Park Geun-Hye would attend the broader commemorations -- but no final decision has been made on whether she will attend the showpiece parade.

- Parade route -

The centrepiece of the parade route is through Tiananmen Square, the symbolic heart of the Chinese state, and the Forbidden City on the north side of the plaza will be closed for two weeks from this Saturday.

China's imperial palace during the Ming and Qing dynasties, it is a UNESCO World Heritage Site and regarded as Beijing's top tourist attraction.

The closure was due to "work arrangements and demands", a notice on the Palace Museum's ticketing website said.

Curfews will be imposed in Tiananmen Square and the nearby Wangfujing shopping centre during rehearsals this weekend and for the actual parade, state media reported previously.

A search Thursday on the website of the five-star Grand Hyatt hotel, next to Wangfujing, showed that the facility "is not available" for four days until September 4, saying it "is either sold out or not yet open for reservations".

"There will certainly be some changes to our opening hours," a hotel spokesman told AFP, without elaborating, adding it would also be subject to restrictions during the rehearsals.

Beijing Capital International Airport and the smaller Nanyuan airport will be closed for three hours on the morning of the parade, earlier state media reports said, and a two-day stock market holiday has been declared.

Measures have also been imposed to try to ensure blue skies in the notoriously polluted city, for both the parade and the World Athletics Championships which begin in the capital on Saturday.

Steps imposed from Thursday include odd-even licence plate restrictions on private vehicles, factory shutdowns and curbs on construction in the capital and nearby regions.