By Pravit Rojanaphruk

Victory Monument and surrounding roads - Bangkok's traffic centre - was shut down by hundreds of anti-government taxis drivers, motorcyclists and 5,000 protesters as they stepped up the pressure on the Abhisit Vejjajajiva administration and on privy council President Prem Tinsulanond to resign.

The immediate effect was a paralysis of Bangkok's traffic as more red-shirt Democratic Alliance Against Dictatorship (DAAD) protesters kept arriving in the evening and vowed to stay put until their goals were achieved.

Pricha Jaibantad, 48, a taxi driver originally from Chiang Mai, said taxi drivers were communicating among themselves through intra-taxi communication channels and FM 107.5 taxi community radio. He said there was no obvious leader but the group was clear about its goals.

"We will shut more roads down," he said, adding that he and his peers would stay on until this government and Prem were ousted.

Asked if he was afraid of another military coup, a police crackdown or attack by the anti-Thaksin Shinawatra People's Alliance for Democracy (PAD), he said no. "We're children of poor and grass-roots people, but we're not afraid."

By 5pm, protesters cheered as taxi radio broadcast Announcement No 2 from the DAAD leadership, that they would no longer recognise Abhisit as the legitimate prime minister of Thailand and that the protesters were urged to fight the government as if fighting "a group of outlawed bandits."

Two dozen taxis began the surprise move to block the Victory Monument shortly after 1pm and there were only 200 protesters by 2pm. But the number soon multiplied. Heavy rain poured down shortly after 6pm but failed to dampen the protest as hundreds marched and danced in the rain, singing and chanting as if it was some sort of carnival. Victory Monument is connected to four major roads and all were affected by the shutdown.

At nearby Sam Saen Delta, two dozen cabs were parked. Somboon Srisawang, a red-shirt protester said: "Let's paralyse Bangkok".

Onlookers mostly watched the protest in bewilderment and amusement - some were partial to it.

One woman on an elevated walkway, a beautician in her mid-thirties, was asked if she thought the protesters were hurting the economy and causing major traffic jams,replied:

"What about when those god-damn [PAD] took over the Government House and the aiports [last year]? Did they think of anybody else but themselves?" she said, adding that she's fed up with what she believes to be a double standard in Thai politics, as the PAD leaders are not in jail and whatever the PAD does is regarded as correct.

"Should we just accept that whatever they do is correct?"

Some protesters said the area would likely be the new protest centre as it was effective in bringing the government to its knees and larger and more convenient in accommodating protesters.

In the nearby Din Daeng expressway entrance, another group of taxi drivers combined forces with the so-called "educated red shirts", shutting down the expressway by the afternoon, saying they wanted to prevent the military or police from reaching Victory Monument. More were also marching near Hua Lampong train station in the evening as parts of Bangkok gradually became paralysed.