These are not the feel-good Olympics the Chinese wanted projected to the world. Yesterday the organisers acknowledged they had faked parts of the openng ceremony, "to provide a theatrical effect", conceded the Games lacked atmosphere, admitted to importing a crowd of volunteers and declared they were preparing to sell thousands more tickets to the Olympic Green to generate enthusiasm.

The president of the Australian Olympic Committee, John Coates, said he was unsure why the tanks had been placed outside the media centre and noted the less-than-euphoric mood.

"I think you have got to put a lot of that down to the preoccupation with security," he said. "And they haven't been able to manage the balance between security and creating that atmosphere, I suppose."

The vice-president of the Beijing organising committee, Wang Wei, said yesterday he did not know why the tanks had been put in place or if it was in response to the murder of an American visitor and the serious assault of his wife on day one of the Games.

"I am not the person to deploy all of this. It is meant to be protective to safeguard the security of athletes and everybody," Mr Wang said. "I have been to different Games. I don't think this is a surprise in Beijing."

Yellow T-shirted volunteers have been shipped in to fill the vacant seats of fickle fans who have bought tickets but have found the weather - either steaming hot or wet - too oppressive. "These are volunteers to lead the cheer squads to create good atmosphere," Mr Wang said.

Despite wanting to fill seats, the authorities have also put security on the alert for scalpers. Touting is banned and organisers have enforced measures to prevent on-selling, including having a second form of identification when entering for the opening ceremony. But yesterday organisers said they would look into the scalping of tickets at highly inflated prices for volleyball, fencing and swimming. It is understood several scalpers were detained yesterday.

Yet while the Games have been sold out, some venues have been embarrassingly bereft of crowds - such as the beach volleyball and hockey stadiums.

Mr Wang said two of the 18 venues had attendance figures of more than 90 per cent, six were more than 80 per cent, eight were more than 70 per cent and two were more than 60 per cent.

This comes as the foreign media has become increasingly hostile toward Beijing organisers as their promises and those of the International Olympic Committee about press freedoms have been discarded. Headlines around the world are reflecting a dour mood.

Yesterday the South China Morning Post reported how the mainland Chinese media had been issued with a 21-point plan to censor their Games coverage. For instance, any political issues that emerged at venues were banned from being reported. Earlier, the Herald wrote how Chinese reporters at the volleyball had notebooks and at least one tape-recording confiscated when the topic of Todd Bachman, the murdered associate of the US volleyball team, was raised. Beijing organisers yesterday said one recorder was taken so another journalist could copy the notes.

At yesterday's press conference, Jill Ku Martin, of Radio Free Asia, a non-profit broadcast service sponsored by the US Congress, demanded to know why her Tibetan colleague Dhondup Dansar had approval from the IOC to cover the Games but was barred from China by its Foreign Ministry. The IOC and Beijing organisers had vowed the accreditation card would guarantee entry to the Games as it doubled as a Chinese visa.

Other restrictions on press freedoms, such as plainclothes security forces photographing reporters interviewing subjects, were raised. "Well, you need evidence of that [occurring]," Mr Wang said.