At least eight policemen, including a senior officer, were killed in clashes with protesters in western Nepal's Kailai area on Monday, officials said.A senior superintendent of police, an inspector and six other policemen were killed when the Tharuhat movement's supporters, wielding axes, knives, spears and other weapons, attacked security personnel, an official said.The protesters were demanding a separate Tharuhat province comprising Tarai districts from Kanchanpur to Chitwan, The Himalayan Times reported.