Following the recent spurt in killing of one-horned rhinos in Orang National Park (ONP) that resulted in deaths of two rhinos on April 20 and 21, one more rhino was killed in the park on the night of April 27. Meanwhile, members of the All Darrang District Students' Union (ADDSU) staged a dharna in front of the office of the DFO, Orang Wildlife Division at Mangaldai yesterday demanding an immediate stop in killing of rhinos.