Thailand's government faces an escalating crisis after police repeatedly fired tear gas to break up protesters blockading the parliament building. The clashes led to the resignation of a deputy prime minister. As Ron Corben reports from Bangkok, the strife sets back efforts by Prime Minister Somchai Wongsawat to defuse months of anti-government protests.

Anti-government protesters argue with riot police in front of parliament in Bangkok, 07 Oct 2008

The violence in Bangkok erupted early Tuesday when riot police using tear gas and stun bombs to clear anti-government demonstrators who had barricaded themselves outside the parliament building.

The protesters, led by the People's Alliance for Democracy, unsuccessfully tried to prevent Prime Minister Somchai Wongsawat from making his maiden policy speech.

Police and protesters clashed several times during the day, and nearby hospitals reported more than 100 people were admitted with injuries.

A doctor at the Ramathibodi Hospital says emergency wards are on high alert.

"We are prepared for mass casualty in the hospitals around about three to five hospitals around this area ... bomb or just eye [tear] gas," said the doctor.

PAD supporters, angry over the arrest of two of their leaders, vow to continue their blockade until the government quits.

Deputy Prime Minister Chavalit Yongchaiyudh resigned to take responsibility for Tuesday's clashes. He had been working to negotiate an end to the PAD siege of the prime minister's office building.

Thaksin Shinawatra (File photo)

Protesters accuse Mr. Somchai's government of acting as a proxy for deposed Prime Minister Thaksin Shinawatra. He now lives in Britain, having fled in August to avoid corruption charges. PAD supporters accuse Mr. Thaksin of being corrupt and authoritarian.

A protester named Sam, was among thousands calling for the government to resign.

"The people do not accept this government, so what we ask for, we ask for real democracy not a government of Mr. Thaksin Shinawatra … and this prime minister is the brother-in-law of Thaksin Shinawatra," he said.

Other protesters accuse of the government of seeking to undermine the country's revered monarchy. Wannnisayanam says more people are coming to join the protests despite the clashes with police.

"We've been here for the king - our king. We are not going to let anybody destroy democracy - you see how many people that are coming here," said Wannnisayanam.

The PAD leadership wants to prevent Mr. Somchai's government from passing constitutional amendments that critics say favor Mr. Thaksin. However, the PAD wants to rewrite the constitution so that most members of parliament will be selected by elite groups such as business owners.

Sunai Pasuk, a spokesman for Human Rights Watch's Thai office, says the PAD appears to hope to trigger a military intervention.

"This is a situation where the PAD can conveniently pressure the military to take sides.… It is clear that the crackdown can be categorized as excessive use of violence by security forces and the action of the police today can be directly linked to the policy of Prime Minister Somchai," he said.

In his policy speech Tuesday, Mr. Somchai called for national reconciliation, and said his government is determined to tackle economic problems the country faces.