Ukraine officials said two explosions that rocked an eastern town early Thursday were criminal acts, and that more bombings have been threatened.
Police say the two simultaneous, early-morning blasts near a coal company building and a central market in Makiyivka damaged nearby buildings, but that no one was hurt.
Ukraine's SBU security service said a note was found near the scene demanding $5.4 million and threatening five more bombings later in the day if the sum is not paid. The note said bombs already had been placed around the city.
Makiyivka is located in Ukrainian President Viktor Yanukovich's home region of Donetsk.
Investigators say they are not ruling out the possibility that the attacks were acts of terrorism.