An anxious calm has descended over Nepal prior to Thursday's national election. Voters are to select members of a special assembly that will draft a new constitution, the latest attempt to move Nepal out of its feudal past and into a democratic era. In the unsettled atmosphere, the head of the United Nations mission in the country is expressing concern that any election day violence could trigger a chain reaction. VOA's Steve Herman reports from Kathmandu.

In the wake of recent bomb blasts and allegations of voter intimidation, there are concerns that rivals will immediately retaliate if Thursday's election turns bloody.

The head of the U.N. mission in the country, Ian Martin, speaking to reporters Tuesday, appealed for calm if violence mars the nationwide balloting.

"My fear is not only of the possibility of spasmodic acts of violence, but of then the danger of over-reaction to them," said Martin. "There is a tendency, sometimes, for incidents to be exaggerated in their gravity, and then for that to set off a chain-reaction."

Trouble is most likely in the restive southern region, known as the Terai, where the Madheshi people complain of discrimination, and desire greater autonomy.

Another worry is whether Maoist soldiers, confined to U.N.-supervised camps, will stay there. Nepal's army, under the election rules, is also to remain in its barracks on election day.

There are also concerns that results will be rigged in rural areas, where outright capturing of polling stations by partisans is endemic.

The election will serve as a referendum on Nepal's unpopular monarchy. The Maoists fought a decade-long civil war trying to dethrone the king. Thirteen thousand people died in that war. Also contesting the election, at the other end of the political spectrum, are backers of the 269-year-old dynasty.

Experts say the election will be the most closely observed ever in Nepal. The U.N. role has been as an election adviser, not observer. More than 850 certified observers have arrived in Nepal from around the world.

The head of the Japanese observer mission, Toshiyuki Niwa, says the observers will only be able to sample the nationwide polling, because much of it will take place in remote mountainous areas.

"We have a very difficult challenge," said Niwa. "We would like to cover as many places as possible. But if we are to go to a remote area we are only able to cover one or two [polling stations]. So that is a dilemma that we have."

Thus, the main task of monitoring the election will fall to the Nepalese people themselves. Domestic organizations will dispatch 60,000 Nepalese observers. But they will have no mandate to halt election fraud or other alleged violations. They are merely to report what they see.

Election organizers here have no illusion that Nepal's election will be without incident, but are hoping it will be transparent enough to be seen as legitimate by the ultimate authority, Nepal's people.