Anti-government demonstrators in Thailand have smashed the window of a car carrying the country's Prime Minister, Abhisit Vejjajiva.
Protesters converged on the vehicle outside a hotel in the coastal resort of Pattaya, south of Bangkok.
The protesters, many of them supporters of the former prime minister Thaksin Shinawatra, have recently held sit-ins outside government offices in Bangkok.
They are due to hold a big protest rally in the city on Wednesday.
Correspondents say the ongoing demonstrations could undermine the government as it prepares to host a major regional summit meeting in Pattaya later this week.
Protesters hit and threw objects at the car's windows, breaking the glass
Mr Abhisit took office in December, after a court dissolved the previous government following months of protests by anti-Thaksin groups.
But now the pro-Thaksin lobby is out on the streets, calling for fresh elections.
The red-shirted demonstrators, from the United Front for Democracy against Dictatorship (UDD), claim Mr Abhisit came to power illegally, and accuse the current government of being a puppet of the military.
The pro-Thaksin lobby is on Bangkok's streets, calling for fresh elections
About 50 protesters surrounded Mr Abhisit's car on Tuesday, armed with sticks and what appeared to be a flagpole.
The prime minister's secretary said Mr Abhisit was transferred by security guards into a police car to escape the scene, but protestors managed to smash a window while he was inside.
Mr Abhisit was not hurt during the attack, and later told reporters: "I did not panic. I can still work normally."
The attack on the prime minister was the most violent of the protesters' actions since they began their campaign two weeks ago, with a sit-in outside the main government offices.
The UDD are planning to hold a mass rally on Wednesday in the centre of the Bangkok, and they are hoping up to 300,000 people will attend.
Mr Abhisit appeared on national television on Monday night to voice his concerns about possible violence at the rally.
"We cannot allow a civil war or a people's revolution," he said. "If the situation leads to a riot, the government cannot stand still."
Analysts say any violence at the rally could undermine Mr Abhisit's government as it prepares to host leaders from 16 Asian nations for a summit in Pattaya from 10 April.
These protests are the latest episode in Thailand's long-running political turmoil, with the two sides - Mr Thaksin's supporters and his opponents - unable to accept the other in a position of power.
Mr Thaksin was ousted by the military in 2006 and has been living abroad in self-imposed exile.
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