BANGKOK, Thailand (CNN) -- Two people died Tuesday when Thai police clashed with thousands of anti-government protesters who barricaded Parliament and prevented lawmakers from leaving.
One person died after a car bomb exploded near the protest area, officials said, and Ramathibhodi Hospital officials confirmed that a woman died from severe chest injuries suffered in the clash with police.
More than 420 people have been hurt, hospital officials said. A deputy prime minister who was charged with negotiating with the demonstrators resigned over the crackdown.
The protesters first prevented lawmakers from entering Parliament to hear newly sworn-in Prime Minister Somchai Wongsawat give his first speech to the legislative body.
After the sparsely attended session -- some lawmakers were unable to get through the barricades and some opposition party members boycotted -- the legislators were temporarily prevented from leaving by demonstrators who locked the exits.
Authorities flew in three helicopters to pluck Somchai to safety.
Paramedics say they expect the injury toll to rise as demonstrators continued to clash with police. The anti-government protesters are trying to lay siege to other government buildings near the Parliament in the capital city, Bangkok.
Many set up make-shift fortresses of tires and barbed wires on city streets and tried to ward off an advancing army of policemen in riot gear. Watch police and protesters clash »
The escalating violence led to the resignation Tuesday of Deputy Prime Minister Chavalit Yongchaiyudh, who had been the government's chief negotiator in the crisis.
He said in his resignation letter that he was stepping down to accept responsibility for the breakdown in communication.
Tuesday's flare-up is the latest in an ongoing crisis that has gripped the nation since summer, when anti-government demonstrators, led by the People Alliance of Democracy (PAD), undertook efforts to purge the current Cabinet.
On Sunday, Thai police arrested a key opposition leader as part of its crackdown on the anti-government protests.
Chamlong Srimuang, a PAD leader, was arrested from a polling booth after he cast his ballot in the Bangkok's gubernatorial elections.
Since August 26, the PAD and its supporters have laid siege to the Government House -- the seat of the Thai government -- saying they will not leave until the ruling People Power Party (PPP) and its allies are ousted from office.
Police issued arrest warrants against Chamlong and nine other leaders, charging them with insurrection, conspiracy, illegal assembly and refusal to disperse.
On Friday, authorities took into custody another PAD leader, Chaiwat Sinsuwong.
The anti-government alliance accuses the PPP of being a proxy government for one-time Thai Prime Minister Thaksin Shinawatra, who was ousted in a bloodless coup in 2006.
Thaksin returned to Thailand after the PPP swept into power in December 2007, but fled again in August, just as he was to appear in a corruption case against him.
The PAD contends that the People Power Party wants to amend the constitution so Thaksin does not have to face charges.
The protesters have held mass street demonstrations, some of which ended in clashes with pro-government supporters.
The protests began with the PAD calling for the ouster of Samak Sundaravej, who was then the Thai Prime Minister.
Samak was eventually removed from office after a constitutional court ruled on September 9 that he had violated the constitution by appearing as a paid guest on a TV cooking show.
But opposition party supporters were further inflamed when Samak was replaced by Somchai, Thaksin's brother-in-law. He was sworn in on September 25.
CNN's Dan Rivers and Kocha Olarn contributed to this report.