"The man who broke into the town hall is suspected of being drunk," the official said on Friday.
An Armenian online news outlet, 168.am, reported on Friday that the man threw a grenade out of the window and opened indiscriminate fire. The attacker is reported to be a 36-year-old former Masis councilor.
A town hall employee told the outlet that Masis Mayor David Ambartsumyan had recently returned from a vacation and was not in his office when the suspect broke in on Friday.
A police representative told journalists later on Friday that the attacker shot himself when law enforcement officers were attempting to negotiate with him. The suspect's body was found inside the Masis town hall. There were no injuries among the police.