A clash ensued between security personnel and the United Democratic Madhesi Front cadres after the later disrupted a training on voters’ education in Rajbiraj of Saptari district on Saturday. A group of UDMF cadres barged into Anirudra Secondary School where the training was being imparted on local volunteers, and seized materials related to voter education. At least four UDMF cadres were injured after police resorted to lathi charge. Three of them were taken to the Sagarmatha Zonal Hospital, while the fourth person with serious injuries was referred to Dharan-based BP Koirala Institute of Health Sciences. Later, UDMF cadres protested the police action, burning tyres at several places in the district headquarters.