By Charles Haviland
BBC News, Kathmandu
The Madheshi community is fighting for a federal system
Burnt-out buses, shattered glass, blaring curfew orders, jittery looking security forces, burning tyres, trees felled across the highway and angry demonstrators.
Until Thursday this was how south-eastern Nepal looked.
Part of the extensive flatlands or Terai, it was ablaze with the anger of Madheshis, or southern Nepalese, complaining that the state discriminates against them.
Violence, leaving over 25 dead, has cast a shadow over a country at a time when the United Nations has been rolling out its new peace mission to consolidate the end of the Maoist insurgency.
And the agitation is not over yet, it is merely suspended for 10 days, insists the chairman of the Madheshi Janadhikar Forum (MJF), Upendra Yadav.
He refuses even to talk to the government unless Home Minister Krishna Sitaula is sacked and the deaths are investigated at the highest level.
He told the BBC there would be "strict action" if the 10 days passed without results.
In future he wants an autonomous Terai state within a federal system.
The recent troubles have brought to the forefront issues of regional and ethnic identity never before aired so prominently.
There are problems in defining the Madheshis, but they have very real grievances.
They are peoples speaking languages also spoken across the border in India, such as Maithili.
"From west [Nepal] to east, we have linguistic links and the same food habits and livelihoods," says Madheshi academic Bijay Karna.
Madheshi protesters have often turned violent
Most of Nepal's small Muslim minority is also Madheshi.
But there is disagreement on whether the category also includes Tharus, an indigenous ethnic group living throughout the Terai.
There are some senior Madheshi politicians, such as the deputy speaker, and one of the seven ruling parties is a Madheshi party.
But, considering more than one in three Nepalese is a Madheshi, they are under-represented in power.
Their campaigners say there is not a single one employed at the Royal Palace; that only one of the 75 district chiefs is a Madheshi; and there are very few in the army.
They say they are not trusted by the establishment but are used and exploited.
Many do not even have Nepalese citizenship.
Most of the victims of the recent violence were Madheshi and were killed in what the UN has called excessive use of force by the police.
Many of their demonstrations have been non-violent. In the troubled town of Inaruwa we were escorted into a meeting of the Madheshi Intellectuals' Forum, whose leaders addressed us with great courtesy.
But there has also been brutality among the Madheshi demonstrators, including the MJF which professes to be non-violent.
Demonstrators have attacked police and others with swords and bows and arrows.
Last Wednesday, after at least two protesters were killed by police in the city of Biratnagar, a crowd locked non-Madheshi local residents inside their houses and set fire to them. Prompt action by the fire services prevented casualties.
Certainly not all the violence has come from the MJF. Reports say criminal elements have entered from India to take advantage of the trouble.
The government and the Maoists have both accused "royalists" and Hindu activists of involvement - three royalist former ministers have been arrested and locked up without charge for three months.
Madheshi academic Bijay Karna believes there has been some such infiltration, "but not large-scale".
Notably, Wednesday's violence began when the crowd tried to storm a prison in which one of the former ministers and an Indian gang-leader are being held.
Madheshi leader Upendra Yadav has warned of strict action
There are also two avowedly militant Madheshi groups involved - the two factions of the Janatantrik Terai Mukti Morcha (JTMM) which are waging an insurgency and have radical demands including the seizing of Terai land owned by non-Madheshis (Pahadis, or hill people).
Resulting from all this violence, a stream of non-Madheshis have now fled the Terai or moved from villages to towns.
They include ordinary people warned to get out at dead of night; people whose houses were burned; journalists threatened with their lives because activists disliked their reporting.
Nepal's politicians, most of whom are indeed people of hill origin, have struggled to respond to all this.
The ruling parties, keen to have credibility with the Madheshi lobby, have mostly said they support their demands.
Prime Minister GP Koirala says the widely criticised new constitution will be changed to give the Terai the number of constituencies proportionate to its population and make the country federal.
The Maoists seem confused.
The protesters bracket them together with the government.
For the first time, the Maoists have seen effigies of their leader, Prachanda, burned in public.
The protests have been spreading
Prachanda's initial reaction to the Madheshi violence was that he would "not negotiate with criminals and gangsters" - ironically echoing King Gyanendra's description of the Maoists.
But to a large extent the Maoists have encouraged the growth of regional sentiment.
To attract support while rebels, they formed ethnically based fronts for their party and drew up a map in which Nepal was divided into regions named after ethnic groups.
The JTMM originally broke away from one such front in 2004, much to the Maoists' anger - and now its two factions, under different leaders, have taken up the Maoists' old role as insurgents.
Even though some commentators now favour regionally-based federalism, many criticise the Maoists' ethnic model.
Nepal has more than 100 ethnic groups and castes, but they are very mixed up with each other.
There are signs that the Maoist leadership may feel they made a mistake in carving up the country on a map. On Friday deputy leader Baburam Bhattarai said it was essential to advance "politics based on class ideology, while integrating ethnic concerns".
Yet regional and ethnic sentiments are now growing, not only among Madheshis. Countless others also feel marginalised and impoverished.
In the past few weeks, there have been strikes by the Tharus of the Terai, western hill people, eastern hill people, and an umbrella body - the Nepal Federation of Indigenous Nationalities (NEFIN).
On Sunday, more than 15 people were injured when yet another group, wanting autonomy for one south-eastern district, tried to enforce a strike.
NEFIN told the BBC it wants to discuss an ethnic federal system with the government.
To many, these developments are not surprising, given Nepal's pro-democracy uprising last year and people's desire for concrete, radical changes.
"We are now coming into a new arena of politics where the various ethnic, linguistic, cultural, geographical groups in Nepal are clamouring for identity," says Nepali Times chief editor Kunda Dixit.
"We need a political system that gives them a voice."
The current unrest has put the grievances of minority groups on the agenda.
The question is whether the government - which will soon include the Maoists - has the vision to accommodate them in some way without allowing a flare-up of communal sentiment - something Nepal has avoided in the past.