SHANGHAI -- Shanghai police have been put on a "crisis" footing as part of a campaign to ensure public security during Olympic football matches in the city next month.

"We have made adequate preparations for the football, and are confident of ensuring safety during the Games," said Cheng Jiulong, deputy director of the Shanghai Police Department and head of the Shanghai security office for the Olympics.

Cheng stressed that security personnel must work with a "sense of crisis", and spare no effort to maintain law and order in the city.

Shanghai will host 12 Olympic football matches during the August 8 to 24 Beijing Games.

Shanghai Stadium, the soccer venue, had been closed for security checks since July 20, with police and armed police conducting round-the-clock patrols.

Fire fighters, engineers, and medical staff would be deployed at the venue to guard against explosive, nuclear and biochemical attacks.

Random identity checks would also be conducted near the stadium and in heavily-congested commercial areas such as Xujiahui, he said.

Hu Shunkang, also of the Shanghai Police Department, said surveillance cameras had been installed on 1,500 buses passing the stadium and extra security checkpoints were set up at airports, and subway and rail stations.

Sales of explosives, and toxic and radioactive materials were suspended from July 20 to August 25, and civilian air traffic over the city would be halted during the football matches, Hu said.

The police also announced rewards ranging from 10,000 to 500,000 yuan (US$1,449 to 72,463) for information on serious crimes.

"With our successful security maintenance experience in the meetings of APEC and the Shanghai Cooperation Organization, we are confident of ensuring a safe Olympics in Shanghai," Cheng said.

His statement came as the funerals of six police officers killed in a stabbing attack on July 1 were held on Wednesday.

Fang Fuxin, Zhang Yijie, Ni Jingrong, Li Ke, Zhang Jianping and Xu Weiya were allegedly killed by 28-year-old Beijing man Yang Jia at a police branch in the Zhabei district of Shanghai.

The security guard of the branch and three other policemen were still in hospital being treated for injuries.