Police had arrested four Kirat workers two weeks ago for collecting donation and begun action against them.
Superintendent of Police Rabindra Sharma said they protesters have been demanding unconditional release of their friends.
Among others, Prem Rai, Kiran Tamang, Khagendra Limbu and Saru Rai have been taking part in the protest programme.
PHOTOS: Police arrest Chand-led CPN cadres as they stage protes...