By Ross Adkin
KATHMANDU (Reuters) - Police in Nepal said they shot and injured at least three protesters on Monday, a day after the Himalayan nation adopted its first democratic constitution, the violence dashing hopes that the historic event would put a stop to weeks of clashes.
The demonstrators were in critical condition after police opened fire at an anti-constitution protest in the city of Biratnagar, said Pramod Kharel, a deputy police superintendent in the Morang district of southern Nepal.
"The confrontation between police and anti-constitution protesters is ongoing," he added.
President Ram Baran Yadav on Sunday promulgated Nepal's new constitution, despite fierce opposition by minority groups in the southern plains whose homeland will be split up under the charter.
The two earthquakes that killed more than 9,000 people in Nepal this year galvanized politicians who had squabbled for seven years to finish the charter.
It creates seven states in a secular, federal system, but is opposed by some groups who wanted to re-establish Nepal as a Hindu nation, and others who feel it is unfavorable to people in the plains, near India.
More than 40 people, mostly protesters, have been killed in recent weeks in clashes over the plan.
Giant neighbor India, which shares a border with Nepal, has watched the violence with concern.
On Sunday, New Delhi issued a frosty statement offering its "best wishes to the people of Nepal," but stopped short of congratulations on the new constitution.
"India has supported a federal, democratic, republican and inclusive Constitution," the Ministry of External Affairs said in the statement.
"We are concerned that the situation in several parts of the country bordering India continues to be violent."
Nepal's government says an imperfect document is better than nothing, and it can be amended to reflect the aspirations of dissenting groups.
In the capital, Kathmandu, former Prime Minister Baburam Bhattarai lamented that the document failed to unite the country.
"I am not completely happy with the announcement of the constitution," Bhattarai told the Annapurna Post daily. "We were not able to involve half of the country's population in this process of creating the constitution."
Kathmandu was preparing for a celebration rally on Monday, but officials in the south were watching for further violence.
Thousands of people in Morang attended competing rallies on Sunday held by supporters and opponents of the new document.
A curfew stayed in place on Monday in nearby Parsa, lifted only briefly in the morning after police shot three protesters on Sunday for defying orders to keep off the streets.
(Writing by Krista Mahr; Editing by Clarence Fernandez)