Police on Saturday arrested a cadre linked to Biplav-led Communist Party Nepal (CPN) in a search and sweep operation launched after a Nepali Congress candidate was injured in a booby trap in the district. Police arrested 42-year-old Dilli Ram Acharya alias Rajan of Purbi Belaka Municipality-7 today, acting Chief District Officer Kumar Bahadur Khadka told Republica Online. On Friday, police had arrested CPN District Secretary Baburam Sharma from the same area. As many as seven people including Federal Parliamentary candidate of Nepali Congress Narayan Karki were injured in a booby trap in Udayapurgadhi Rural Municipality three days ago. Police have rounded up Dainik Acharya, Subedi and Bal Bahadur Magar in the last three days. Magar, considered as one of the masterminds behind the explosion, was arrested from his own house on Thursday. With this, a total of those arrested for their involvement in the anti-election activities has reached nine. Earlier, police had arrested District Member Purna Bahadur Katuwal, Kamala Tamang, Uddhav Pradhan, Shyam Bhujel and Bandana Paudel. Police have beefed up security after CPM-UML Chairman KP Sharma Oli was scheduled to arrive in the district to address an election rally organized by the left alliance today. The election rally is taking place at Tharuhat-Triyuga stadium in Gaighat.