Thailand's anti-government protestors are back on the streets, and so are armed troops. Here we go again.

September 19 marks the fourth anniversary of the 2006 military coup which saw the prime minister Thaksin Shinawatra removed from power. To mark the occasion his supporters, the red shirts, are once again holding rallies around the country.

They're also trying to pressure the government into releasing more than 250 people who have been detained since the end of their protest in May which saw violent clashes with the military.

Some of the activities are taking place in Bangkok, which is still under a state of emergency, meaning that, among other things, political gatherings of five people or more are banned. Despite this, the government says it will allow the protestors to assemble, as long as they don't break the law. Aren't they doing that simply by gathering?

What this indicates is that the red shirts are regaining confidence and will not back down in their quest to bring about political change. In fact they're now saying they'll gather once a week.

This is all taking place as the rice harvest comes to an end. Most of the red shirt support base comes from the rural communities, and once harvesting finishes, in theory they'll be available to join the rallies again.

After the violence of the previous protest which ended on May 19, the government set up a truth and reconciliation commission to find out what led to the street fighting and to try to bridge the divide in the population. It says it will take two years to complete its work, by which time there are sure to be many more chapters in Thailand's troubled political story.

And given how quickly the red shirts have regrouped, reconciliation maybe a long way off.