Malkangiri district Collector D Prashant Kumar Reddy said Aadhar enrolment operation in the area has been suspended after the incident.
A group of armed ultras struck when Aadhar enrolment was in progress at Tekguda primary school in Kalimela area, about 50 km from here yesterday, the district Collector said.
After surrounding the enrollers, the naxals took away four of the seven personnel from the enrolment venue into the nearby forest, he said.
Efforts were on to recover the laptops and other gadgets taken away by the ultras, he said.
The four personnel were set free with a warning that the enrolment process be stopped, he said. The rebels have sent a letter asking officials to halt the enrolment drive in the region forthwith, the police said.
Security has been tightened in the area after the incident and investigation is on, Inspector In-Charge of Kalimela police station S K Nayak said.