The battle for control of Bangkok today forced Thailand's Red Shirts to end their anti-government protest as fierce fighting left four dead.
Protest leaders said they would surrender to authorities to prevent more deaths.
The announcement came after the army overran their heavily barricaded encampment in central Bangkok.
Seven Red Shirt leaders went on stage in the core protest zone to announce their decision, which was greeted with shouts of dismay from the men and women gathered around.
Protest leader Natawut Saikua said "we have done our best".
At least eight people died in the latest fighting, with one foreign journalist -- believed to be Italian -- getting shot in the chest. Two other foreign journalists were wounded by bullets.
Surreal scenes of warfare erupted in one of the ritziest parts of the capital, as troops armed with M-16s marched through the central business district past upscale apartment buildings to retake the area around manicured Lumpini Park, which has been under the control of protesters camped there for weeks.
Government spokesman Panitan Wattanayagorn declared the first stage of the army operation to secure the area around Lumpini Park successful and said that some protest leaders had fled.
However, two of the three key leaders remained in the protest zone giving defiant speeches and singing on a stage, as troops drew closer.
A reporter who followed the troops into the protest camp saw the bodies of two men sprawled on the ground, one with a head wound and another apparently shot in the upper body. They were the first known casualties in the assault that began before dawn today on a one-square kilometre (three-square kilometre) stretch of downtown Bangkok that protesters have occupied.
Troops fired M-16 rifles at fleeing protesters and shouted, "Come out and surrender or we'll kill you". A photographer saw three foreign journalists shot.
The army action came after weeks of defiance by the protesters who are seeking to oust the government of Prime Minister Abhisit Vejjajiva.
The violence in Bangkok, a popular stop for tourists heading to Thailand's world-famous beaches, has caused concern internationally and raised doubts about the stability of this Southeast Asian nation.