The police that are guarding the area around the mayor's house have already detained a man who has reportedly thrown the grenade into the Sadovys' house, the press service of the Interior Ministry's main department in Lviv region said.
It has been established that the detainee is a 29-year-old local resident.
The grenade exploded in the yard of the mayor's house in Lviv at about 22:50 local time on October 29. No casualties were reported.
Investigators and mine clearance specialists are working at the site of the incident. Chief of the Interior Ministry's main department in Lviv region Dmytro Zaharia, Chief of the SBU Security Service's department in Lviv region Viktor Andreychuk and Lviv Regional Governor Oleh Syniutka are also present.
As UNIAN reported earlier, unidentified men attacked mayor Sadovy's house with the use of a grenade launcher in December 2014. No casualties were reported.