The strength of Maoist-backed tribal outfit Chasi Mulia Adivasi Sangh (CMAS) leader Nachika linga, allegedly involved in nearly 30 Red offences, seems to be on the wane following the surrender spree of Sangh activists. According to officials, while nearly 950 tribals belonging to 22 villages under Narayanpatna block of Koraput district have deserted the outfit in the past four months, as many as about 500 CMAS supporters appeared before the Narayanpatna police to shun violence on Wednesday.