Tymoshenko is serving a seven-year prison sentence in Ukraine after being convicted on charges she abused her authority when she helped broker a 2009 natural gas deal with Russian energy company Gazprom. She denies the charges and claims prison authorities have abused her.
Pia Ahrenkilde Hansen, a spokeswoman for the European Commission, said leaders in Brussels won't attend any events in Ukraine given growing concerns about Tymoshenko's treatment.
Dennis Abbot, a spokesman for the European Sports Commissioner Androulla Vassiliou, said there was growing frustration with Kiev given plans for the Euro 2012 soccer tournament in May.
"If the current situation stands -- this situation regarding human rights in Ukraine, and in particular the situation regarding the treatment of Mrs. Tymoshenko and other opposition figures -- then the commissioner feels that it would be entirely wrong to go to Ukraine," Abbot was quoted by Radio Free Europe/Radio Liberty as saying.
Kiev charged European officials were "making sports a hostage of politics" by adopting "Cold War" policies.
At least two dozen people were injured in a series of bomb explosions Friday in the Ukrainian city of Dnepropetrovsk, Tymoshenko's home town.
Boston schools pull out free condoms over wrapping complaints
NBC reportedly holds celebs hostage to Jimmy Fallon's show