The Madhesi and Tharu mainly live in the southernmost part of Nepal, an area known as Terai.

CNN: Beleaguered Nepal enshrines its new constitution

They also point to insecurity in the southern Terai region, home to around 40% of Nepalis.

ECONOMIST: Nepal

Tribal militiamen in the Terai might accept a more modest bribe.

ECONOMIST: Nepal

Terai accounts for about a fifth of Nepal's land area but is home to slightly more than half of its population, with the two ethnic groups making up just over a quarter of this.

CNN: Beleaguered Nepal enshrines its new constitution