Deadly clashes between Nepali police, protesters
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.
Yesterday’s violence erupted as members of the Tharu ethnic minority 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.