Two relatives of the Nepal Prime Minister Girija Prasad Koirala were shot at in broad daylight in his hometown of Biratnagar on Friday, killing one of them on the spot, state-run Nepal Television reported.
Unidentified gunmen attacked Kiran Arryal, the brother-in-law of Koirala's nephew Shekhar Koirala, and his younger brother Ashish Arryal. Kiran was killed on the spot while Ashish has been admitted to a local hospital, the report said.
Shekhar Koirala, a physician who joined full-time politics a few years ago, is one of the most powerful members of Koirala's Nepali Congress party and has his uncle's ears.
He was a member of the team formed by opposition parties to begin negotiations with the Maoist guerrillas in India last year when Nepal was ruled by king Gyanendra's government.
No one has claimed responsibility for the attacks, the channel said.
The incident comes barely a week after the Nepalese government deployed a Special Task Force in the violence-racked Terai plains to restore law and order.
Biratnagar, Koirala's constituency, has been one of the most violence-hit towns as several groups, some of them armed, began new movements for autonomy.