Adhikari was beaten up at Dhunchepakha before the locals chased the gang to Chapacho and severely beat them resulting in two deaths. Two were critically injured in the incident.
According to Metropoiltan Police Circle Thimi, Adhikari, the college-goer was arrested from Harhar Mahadev, Kathmandu. The 18-year-old is a 12th grader at Crimson College, Sankhamul.
Along with him, police also arrested Pradeep Paudel for alleged involvement in the incident.
Meanwhile, demonstration in protest to the incident started at Sanothimi on Wednesday afternoon.
Basant Lama, one of the critically injured youngster, lives in Sanothimi. Lama is now undergoing treatment at B&B Hospital.
Hundreds of demonstrators blocked traffic burning tyres.
Earlier in the morning, tensions erupted in Koteshwar and Kaushaltar after the identities of the dead ones - Jeevan Gaha Magar and Sabin Mahat Chhetri - was revealed.
NC registers win in Madhyapur Thimi