After a military offensive that crushed anti-government rallies in Bangkok, angry "Red Shirts" are returning to their northern heartland in disarray, with their leaders in custody or hiding.

Hundreds of Reds poured off trains in Thailand's second-largest city Chiang Mai to a hero's welcome after staging rolling demonstrations that paralysed parts of the capital and left 85 dead and 1,900 injured since March.

"I lived in Bangkok for two months. My heart still wants to carry on this fight. This pull back for me is just temporary," said Wirash, a 43-year-old musician.

The Red Shirt military strategist, a renegade general known as Seh Daeng, was shot in the head by a sniper days before an overwhelming offensive Wednesday that forced the movement's top leadership to surrender.

"The Red Shirt does not have leaders now. I do not know what to do. The police have caught our leaders," said Wirash, who gave only his first name. "For now I have no plans to go back to Bangkok."

Wirash echoed the fears of political analysts when he said he believed the shootings of his comrades in several clashes with security forces could "spark a civil war in Thailand."

"This crisis will not end now. The Red Shirt people may adopt other strategies but at the moment we do not have a leader or a plan. We do not have a direction," he said.

Thailand is deeply split between the Reds, mostly urban and rural poor who are demanding the ouster of a government they condemn as undemocratic, and rival pro-establishment "Yellow Shirts" who represent the nation's elites.

A night-time curfew is in place until Sunday in the capital as well as the Reds' heartland in the rural north and northeast, amid fears the trouble could spread. Four provincial halls have already been torched.

"They have gone home with that sense of resentment, that bitterness and it will not end there," said Pavin Chachavalpongpun from the Institute for Southeast Asian Studies in Singapore.

"So it will be no surprise if we hear of more violent riots across the country, especially the north and northeast, because these people do not have faith in the election process, so they turn to violent alternatives."

Pavin said that having large numbers of Reds, with no hope and nothing to lose, roaming around without a leadership was a major problem for Prime Minister Abhisit Vejjajiva.

"There's a loss of communication between Red Shirts and I think it's very dangerous for the government because they need to deal with the Red Shirts and they don't know where they are, or who they are receiving instructions from."

For now, Abhisit wins

Chiang Mai is the home town of the Reds' hero, ex-premier Thaksin Shinawatra who was ousted in a 2006 coup. His elected allies were ejected by a court ruling, and Abhisit was appointed in an army-backed parliamentary vote.

Thaksin is idolised by many Reds for his populist policies, including cheap healthcare and village funds. But Thailand's elites see him as corrupt, authoritarian and a threat to the revered monarchy.

For now, the anti-government force in Chiang Mai seems impotent. Outside the train station, a lone Red on a motorcyclist and carrying a Red flag rode round and round in circles.

Another man yelled into his mobile phone, relating the events in Bangkok and cursing the military while a group of policemen stood next to him, smiling mildly.

"Here in Chiang Mai the locals want to fight back. But there is a lack of leadership and members here do not have much organisational skills," said Dej Khiaonarong, a Red Shirt sympathiser.

Many returning protesters went back to their villages and untended paddy fields, while others were trucked to a nearby Reds radio station, where supporters pressed them with packets of food and bottled drinks.

Nikhom, a local Red Shirt leader who welcomed the protesters at the radio station, said the curfew had temporary halted their plans to organise new gatherings.

"But people are very angry with Prime Minister Abhisit. For now Abhisit you win. But we are not giving up our struggle," he said.