Amnesty International on Thursday urged EU diplomatic chief Federica Mogherini to use a visit to Iran this weekend to demand that Tehran immediately release all imprisoned human rights activists. London-based Amnesty called on the European Union to take a tougher stance as the group published a report accusing Iran of a "vicious crackdown" that it says has dashed hopes of rights reform under President Hassan Rouhani. Amnesty's Iran researcher Nassim Papayianni said the rights organisation is urging Mogherini to request a meeting with jailed human rights defenders, and ensure they are not targeted later as a result. "We would also call on her to forcefully call for the release, immediately and unconditionally, of all human rights defenders that are imprisoned in Iran," Papayianni told AFP. The Amnesty report published Wednesday highlights 45 cases of activists, some of whom were jailed for 10 years or more for simple acts such as being in contact with the UN, EU or human rights organisations including Amnesty International. Shorter prison sentences were handed down to activists fighting for justice in cases of mass extrajudicial executions and enforced disappearances in the 1980s. Papayianni said Mogherini should ask to meet with activists including Narges Mohammadi, the former head of the Centre for Human Rights Defenders in Iran. Amnesty said the criminal case against Mohammadi was opened in reprisal for a 2014 meeting she had with Mogherini's predecessor, Catherine Ashton. The report's lead researcher Philip Luther said "the EU must not stay silent over the outrageous treatment" of activists and should press for their release "instead of appeasing Iranian officials."  Mogherini's spokeswoman Catherine Ray told a press briefing Thursday that her boss would "raise the topic" of human rights when she visits Tehran for Rouhani's inauguration ceremony on Saturday. "Human rights remain a central feature of our engagement with Iran," Ray said, without saying whether she would call for the activists' release.