In Orissa, police arrested six Maoists, involved in a series of attacks including blowing upof a police outpost.The police sources said that they were nabbed in Sundargarh district on Tuesday.Rourkela Superintendent of police said that ultras who belong to Jheripani village, were involved in blasting the police outpost and CITU office building at Kalta last year. Two landmines hidden by the ultras and weighing 30 kg and 10 kg were seized during a combing operation from the jungle under Koida police limit.