Police identified two victims of the accident as the 37-year-old leader of the Nepali Congress-aligned NSU and her car driver Dhruva Karki (42), a permanent resident of Mahadevsthan in Kavre district.
Pokharel was the President of Free Students Union of Kathmandu-based Padma Kanya Campus.
The car (Ba 3 Cha 8097) heading toward Hetaunda from Pathalaiya along the East-West Highway had collided head-on with a passenger bus (Na 4 Kha 5696) in Amlekhgunj-6 at around 4:45 am today.
Both had died on the spot.
Police said two others, Govinda Bahadur Budhathoki (35) and Pradeep Pokharel (32) from Triveni-2 of Udayapur district sustained injuries. They are undergoing treatment at the Birgunj-based Narayani Sub-Regional Hospital.
Further investigation is underway.