Security forces resorted to firing – mostly rubber bullets and tear gas - in a bid to control the protesters and to restrict access to the rally site at Rajprasong in central Bangkok's hotel and commercial district. A mass transit skytrain station in Silom was attacked by M79 grenades.

The operation is an effort by Prime Minister Abhisit Vejjajiva to end the two month long anti-government protests that have led to increasing costs to the economy. The government has also extended an emergency decree to 15 other provinces in order to prevent more protesters from traveling to the capital.

On Friday clashes between security forces and protesters killed at least seven people. Dozens were injured, including a foreign journalist. Since the rallies began in mid-March over 30 people have died and more than 1,000 were injured.

'Dangerous situation'

Key roads were closed, mass transit systems were disrupted and many shops and businesses were shut for the day in areas close to the anti-government barricades.

Sunai Pasuk, representative for Human Rights Watch in Thailand, says the situation is becoming increasingly difficult for the government.

"This is a very dangerous situation. The government needs to operate with extreme care the rules of engagement – the use of lethal force can only be approved in order to protect public safety and in the case of self defence. Nothing should be allowed beyond that. I am very concerned."

But Pakdee Tanapura, a spokesperson for the Red Shirts, said they were ready to fight if the military went ahead with its blockade, which included the cutting off of power and electricity and water to the protest site.

"The decision is that they would fight all the blockading. It will cause them to fight back. They are now calling people around Bangkok to move in and to help."

Red Shirt leader's condition critical

Late Thursday a sniper cut down a key Red Shirt leader. Army Major-General Khattiya Sawadipol, also known as Seh Daeng, who led security at the red shirt barricades. He is suspected to have been responsible for grenade attacks against pro-government demonstrators in late April. He remained in a critical condition in hospital. But there was little sympathy for the man in the Silom area of Bangkok, now under military protection.

A resident Mr Lek says Seh Daeng was a bad person and the red shirt rally was taking an increasing toll on the local economy in Silom and Rajprasong.

Hardliners remain defiant

Up to 30,000 troops and police have been deployed as part of the operation.

The military action followed the collapse of a reconciliation road map put forward by Mr. Abhisit. Human Rights Watch's Pasuk says it appears some moderate Red Shirt leaders have fled the protest site.

"The hardliners have taken over command so with that we don't have any voices of reason left in the decision making of the Reds," says Pasuk. "The decision to react will be drastic."

Exiled former Prime Minister, Thaksin Shinawatra, who is widely supported by the Red Shirts, called for new talks to avert further violence.

Author: Ron Corben (Bangkok)

Editor: Thomas Baerthlein