Krishna Charan Shrestha, a member of the Rastriya Prajatantra Party, was shot outside his home by three gunmen on motorcycles at Belaha village in Siraha district, 150 km east of the capital, Kathmandu.

"He was rushed to the hospital where he was declared dead," a police officer told Reuters, adding that one of Shrestha's aides was also wounded in the attack.

Authorities said that two of three assailants were later caught and killed by villagers, but it was still not immediately clear who they were or why the politician had been killed.

Shrestha's party is the fourth largest group in the Himalayan nation's parliament, but it is not a member of the seven-party alliance that rules the country now.