Five people were arrested on June 5 in Arunachal Pradesh's Lower Siang district in connection with the incident of firing at the State's border with Assam in which two persons were killed, police said.
The accused were arrested, and kept at the Likabali police station, police spokesperson Rohit Rajbir Singh said.
They were identified as Bagam Tasso, Igip Tasso, Mikjom Tasso, Bompar Tasso and Yongam Nguba, he said.
"Police are trying to recover the weapons used in the incident, and interrogation is on to unearth the truth," he added.
Two persons died in Assam's Dhemaji district on Monday after alleged firing along the inter-State border.
People of Dhemaji had organised a plantation drive at the inter-State border area on the occasion of World Environment Day. Some villagers had gone in advance to make the arrangements. They allegedly came under firing, in which one person died on the spot, the Assam Police said.