SIMARA, Nepal (Reuters) — Violent protests by ethnic Madhesi people in Nepal's southern plains that left five dead in recent days could set the stage for wider communal conflict if grievances are not dealt with quickly.Analysts say the military could be forced to intervene, further tarnishing a much-lauded peace process between Maoists and the government that has seen the former rebels join an interim parliament after a decade-old conflict.

"If the government does not respond quickly and comprehensively, it could be dealing with a bigger problem than it had with mainstreaming the Maoists," C.K. Lal, a political analyst in Kathmandu, said on Saturday.

"If the violence spirals, it could be a pretext for the army to step in as it will not tolerate the country moving towards chaos," he said.

"Most terrifying, it could result in communal clashes. Sort of each man for himself," Lal said.

Ethnic Madhesis are linked more closely in language, dress and culture to Indians living across the border than with Nepal's ruling elites, who come largely from the country's Himalayan mountains.

The Madhesis say they have not been given a fair share of power and want their rights and contributions to the nation fully recognised.

They live along a fertile strip of land along the Indian border called the Terai, Nepal's agricultural and industrial heartland that is home to nearly half the country's 26 million people.

The protests over the past ten days has led to police firing, rioting, attacks on politicians' houses and clashes forcing authorities to put major towns under curfew in the Terai's picturesque mustard, wheat and paddy fields.

Ian Martin, personal representative of the UN Secretary-General to Nepal's peace process, said he was dismayed at the violence which, if it continued, could delay elections for a special assembly that will draft a new constitution and decide the fate of the monarchy, a key Maoist demand.

"The efforts we are supporting to make (the elections) possible on the agreed schedule can only be jeopardised if the situation in the Terai continues or escalates," Martin said.

Nepal does not have a history of major ethnic clashes but local leaders say tension is rising as a result of the protests.

Madhesi activists say the community is poorly represented in the top echelons of the government, army, police and judiciary and in the highest posts of political parties.

Local journalists say it is imperative the government, with the support of the Maoists, assures the community that parliamentary constituencies will be redrawn, guaranteeing the populous Madhesis a bigger say.

"We need to be sure of having sufficient representative power in the constituent assembly so we have a say in deciding Nepal's future," said Surendra Kurmi, a leader of the Nepal Sadbhavana Party, a small Madhesi-dominated party that is part of the ruling seven-party alliance.

The government blames "reactionary" forces for the trouble and says it is ready for talks with protesters.

"We must solve the problem peacefully through a dialogue. Otherwise reactionary forces will raise their heads," Prime Minister Girija Prasad Koirala told reporters.

Analysts say the end of royal rule last year, greater freedom for Nepalis and a fluid political system has forced simmering Madhesi anger to boil over.

Chandra Kishor, editor of a local news magazine, Terai, said the situation in the region was "highly inflammable".

"There are lot of vested interests who are eager to supply oxygen to the fire," Kishor said in Birgunj, a major trading point on the Indian border.

The town of around 250,000 people was still under curfew on Saturday after clashes between police and Madhesi activists who burnt tyres and attacked a police post.