Police have closed off and are guarding the area around ER in Veliko Tarnovo, where a visitor in the hospital found a discarded hand grenade and sent a signal to the emergency telephone, BNR reported.
A National Military University team is about to defuse the grenade.
Further information will be provided.
Acting US Defense Secretary Mark Esper is making it clear to Turkey that it will face economic sanctions if it goes ahead with the purchase of a Russian missile defense system.
Esper met with Turkish Defense Minister Hulusi Akar on Wednesday during a NATO meeting. Officials say there was no progress in the stand-off between the two allies.
A group of self-styled anarchists lobbed homemade firebombs at riot police near the downtown Athens district of Exarchia in the early hours of Saturday but there were no reports of injuries.
The group attacked a riot police unit which had been stationed at the junction of Patission and Tositsa streets at 1.50 a.m. with a hail of Molotov cocktails.