A 37-year-old former municipal employee has been arrested in connection with three bomb explosions in the public garden near the town hall, reports said on Tuesday.
State broadcaster CyBC said the man denied any involvement.
He had been sacked from the municipality three years ago for various offences.
Police are questioning him over three blasts in December, last Thursday, and last Sunday.
The devices were made of a fire extinguisher blown up using camping gas canisters, which were detonated with flammable material.
No injuries or damages were caused.