United Nations, September 4 (RHC)-- The United Nations has called for an end to violence in Nepal following a series of deadly clashes between police and demonstrators protesting against a proposed constitution.

The spokesman for UN Secretary General Ban Ki-moon, Stephane Dujarric, said in a statement on Thursday that the UN chief was "concerned about reports of violence in recent weeks and saddened by the loss of life."

Ban has reiterated that the ongoing crisis in Nepal should only be resolved through dialogue, Dujarric said. "He (Ban) urges all to refrain from the use of force, denounce violence in all forms and engage in dialogue."

Meanwhile, an international NGO has also urged major Nepalese political parties to "recognize the depth of discontent and the fundamental challenge this poses to the legitimacy of the proposed constitution."

"A botched solution risks entrenching communal polarization in society and radicalizing groups that feel their concerns were not seriously considered," the International Crisis Group (ICG) said in a statement on Thursday.

The new national constitution aims to restructure Nepal as a federal state made up of seven provinces, and draw a line under the issue of a decade-long civil war that ended in 2006.

Local administrations in Nepal have already imposed overnight curfews in several districts to prevent street demonstrations.