Amid violent protests, Nepal on Sunday adopted its new fully secular and democratic constitution, PTI reported.

"I announce the presented constitution of Nepal, passed by the Constituent Assembly and authenticated by the chairman of the Constituent Assembly, effective from today, 20 September 2015, before the people of Nepal," Nepal President Ram Baran Yadav said at the country's new Parliament.

"I call for unity and cooperation of all at this historic moment," he said at the special ceremony at the Constituent Assembly (CA) hall in Naya Baneshwor. The decision, however, saw several violent protests across the country. At least one person was killed and17 were injured at Maisthan of Birgunj after police opened fire on violent protesters on Sunday afternoon.

The Himalayan Times reported that two injured protesters had to be airlifted to Kathmandu as their injuries were grievous.

Several lawmakers and Nepali politicians also bore the brunt of public anger. A group of protesters attacked and burned down a house belonging to Nepali Congress leader and Constituent Assembly member Sitadevi Yadav.

The protesters opposing the promulgation of Nepal's Constitution also vandalised the house of CPN-UML lawmaker Raj Kumar Gupta in Birgunj of Parsa on Sunday evening.