"The Election Commission has decided to count the postal ballots in Kanchanpur (north Tripura) May 16," Kanchanpur sub-divisional magistrate Nantu Das said.
He said: "This was decided in view of the threat given by local NGOs in Mizoram to obstruct counting of postal ballot papers in Aizawl."
Das said Mizoram government officials would count the postal ballot under the supervision of an Election Commission observer.
Till May 16, the postal ballots would be preserved in a strong room guarded by the Central Reserve Police Force.
Polling for the lone Lok Sabha seat in Mizoram will be held April 9.