Bangkok:
Thai security forces using tear gas and rubber bullets on Saturday launched a large-scale crackdown to try to end a month of disruptive protests by anti-government demonstrators in the capital, Bangkok.
Some 161 people were injured in the clashes between security forces and the protesters, mostly by tear gas or suffering from cuts and bruises, the government's Erawan emergency centre said.
Unconfirmed reports said several people had gunshot wounds, though the army said that any live rounds were only fired into the air as warning shots.
Chaotic confrontations broke out in several locations, mostly involving pushing and shoving by the two sides, though some protesters wielded sticks and threw rocks, while security forces fired tear gas and rubber bullets.
The so-called "red shirt" protesters are demanding that Prime Minister Abhisit Vejjajiva dissolve parliament and call new elections.
They claim that he came to power illegitimately in December 2008 with the help of military pressure on parliament.
Government forces have confronted the protesters before but pulled back rather than risk bloodshed.
On Friday, the army failed to prevent demonstrators from breaking into the compound of a satellite transmission station.
The humiliating rout of troops and riot police raised questions about how much control Abhisit has over the police and army.
The military vowed to clear one of the protesters' main encampments by nightfall on Saturday, but by early evening seemed to have failed.
An army spokesman had told the Nation Channel cable TV station that security forces would try to reclaim the rally site near Pan Fah bridge in the old part of Bangkok "before dusk".
The area was occupied by "red shirt" protesters about a month ago.
The government has issued an emergency decree and other orders making the demonstrations illegal.
The army spokesman said that more forces would be sent to a second rally site in the heart of Bangkok's tourist and shopping "to pressure the protesters".
"If the security officers have to use force, they will do it with caution," government spokesman Panithan Wattanayagorn told cable TV network TNN on Saturday.
The new deployment came after protesters were pushed back by water cannons and rubber bullets from the headquarters of the 1st Army Region.
Although they have two main rally sites, the "red shirts" use trucks and motorcycles to send followers all over the city on short notice.
The violence has not yet approached the level of last April, when the "red shirts" began rampaging on city streets and torching public buses.
Abhisit had vowed late on Friday not to bend to the demands of the protesters.
On Friday, the demonstrators broke into the Thaicom transmission station and briefly restarted a pro-"red shirt" television station that had been shut down by the government under a state of emergency.
After scattered hand to hand scuffles, the troops retreated in disarray, some taking positions inside the main Thaicom building. About a dozen people were hurt.
The escalating demonstrations are part of a long-running battle between the mostly poor and rural supporters of former Prime Minister Thaksin Shinawatra, and the ruling elite they say orchestrated the 2006 military coup that removed him from power.
They see the Oxford-educated Abhisit as a symbol of the elite and claim he took office illegitimately in December 2008 with the help of military pressure on parliament.
Thailand's military has traditionally played a major role in politics, staging almost a score of coups since the country became a constitutional monarchy in 1932.
In 2008, the army undercut the government's authority by refusing to move against demonstrators who were protesting against a pro-Thaksin government.