More forces were airlifted to Cheruvuru forests in Chintapalli mandal, where four Maoists were killed in a gun battle with Greyhounds personnel Friday.
The exchange of fire between Maoists and police was continuing for the second day in the area.
Reports reaching the state capital said tension prevailed in the tribal areas on Andhra-Orissa border as additional forces were mobilised for massive combing operations.
Meanwhile, the bodies of the Maoists killed Friday were brought in a helicopter to Narsipatnam in Visakhapatnam district, where autopsies will be conducted.
One sub-inspector of Greyhounds, who was injured in the gun battle, was also shifted to Visakhapatnam and admitted to a hospital.
The police were using three helicopters to airlift additional forces, weapons and materials for combing operations in the deep forests. Forces were also being mobilised from Chhattisgarh.
A senior police official said they suspect presence of about 70 Maoists in the area. As many as 60 kitbags, three weapons, two bags of explosives and solar chargers were recovered from the scene of the gunfight.
The officer said the Maoists belonged to People's Liberation Guerilla Army of the outlawed Communist Party of India-Maoist. The recovered weapons, including an INSAS rifle, suggest the presence of some top leader of the PLGA in the area.
Visakhapatnam, Vijayanagaram and Srikakulam districts bordering Orissa have a significant Maoist presence. In other parts of Andhra Pradesh, a former stronghold of Maoists, the CPI-Maoist suffered huge setbacks with the killing of their top cadres by police over the last four years.