"Nagzira Bandh, Lal Salam, Dum hain toh Nagzira aao (If you dare, come to Nagzira)," the banners said.
'Lal Salam' (Red Salute) is a greeting often found on Naxal pamphlets and banners.
Special Inspector General of Police (Anti-Naxal Operations) Sharad Shelar told PTI that the banners didn't bear the name of any organisation.
Security in the popular wildlife sanctuary has been enhanced and people need not worry, Shelar said.
Gondia in eastern Maharashtra, alongwith Gadchiroli and Chandrapur districts, has witnessed Naxal activities on and off. The district borders on Chhattisgarh.