German President Joachim Gauck has cancelled a visit to Ukraine amid growing concern at the health of jailed former Ukrainian PM Yulia Tymoshenko, the BBC informs. EU foreign affairs chief Catherine Ashton said she was “deeply preoccupied” after reports Ms Tymoshenko was assaulted by guards. The Ukrainian opposition leader alleges that three men punched her in the stomach on her way to hospital. She is said to have begun a hunger strike last Friday. Tymoshenko was jailed for seven years in October after a trial condemned by Western states as politically motivated. She accuses President Viktor Yanukovych, a political rival, of seeking revenge. During a visit on Thursday to commemorate the 26th anniversary of the Chernobyl nuclear disaster, Mr Yanukovych said that he had ordered the prosecutor general to investigate allegations that she had been beaten in jail. “I hope that we will have a concrete answer in the near future.” Ashton’s spokesperson said there had been confirmation from the Ukrainian ombudsperson’s office that the former prime minister had been “subjected to physical violence during the transfer from her cell to a hospital on 20 April”.Ms Tymoshenko’s daughter, Eugenia, told BBC News on Wednesday that she and a lawyer had seen her bruises and that her mother was refusing please to abandon her hunger strike. But the head of the prison in the eastern city of Kharkiv, Ivan Pervushkin, has insisted she was not beaten, Interfax news agency reports. Ms Tymoshenko had shown the “bruises she allegedly received from our guards” only to her own party colleagues, he said. In Germany, some politicians have threatened to boycott games held in Ukraine during the European football championships being hosted jointly by Poland and Ukraine in June, Die Welt reports.