At least six police officers and three protesters have been killed in western Nepal in clashes during demonstrations over a proposed new constitution, an official has said.

Government Administrator Raj Kumar Shrestha told the AP news agency that protesters in Kailali district had attacked police enforcing a curfew.

The official said thousands of protesters attacked the officers with spears, knives and stones.

The wounded have been taken to the regional hospital and the death toll is expected to rise.

The AFP news agency put the death toll of police officers killed at seven.

A new national constitution presented in parliament on Sunday aims to restructure Nepal as a federal state made up of seven provinces.

The protesters argue that the new borders will discriminate against historically marginalised communities.

Tharu minority

Monday’s violence erupted as members of the Tharu ethnic minority had demonstrated to demand their own separate province.

Home Minister Bam Dev Gautam said the government would send troops to the area to try to bring the situation under control, and appealed for calm.

“At a stage when we are heading to a new era … we must call on people to not be involved in activities that disturb social harmony and ignite ethnic hatred,” Gautam told politicians.

He said the area had been declared a “riot-stricken zone” and the army deployed.

Nepal’s main parties struck a breakthrough deal on the charter in June after April’s devastating earthquake helped end years of wrangling that had left the impoverished Himalayan nation in political turmoil.

Work on a new national constitution began in 2008, two years after the end of a decade-long Maoist insurgency that left an estimated 16,000 people dead and brought down the 240-year-old Hindu monarchy. Al Jazeera