Altogether 13 Maoist ultras including a woman were killed in an encounter with security forces inside a forest in Malkangiri district early on Saturday while another rebel was captured. The Maoist group that camped there was suspected to have been involved in the May 25 attack on a Congress convoy in Bastar district of Chhattisgarh that killed senior party leaders V C Shukla, Mahendra Karma and about 19 others.