By Lisa Holland, Foreign Affairs Correspondent
Hundreds of people have been abducted and subjected to horrific beatings in the troubled eastern region of Ukraine, according to campaign group Amnesty International.
After the collapse of the pro-Russian government of President Yanukovych in February this year, Russia seized control of Crimea and separatists in the east of the country have been fighting Ukrainian government forces, prompting the biggest east-west showdown since the Cold War.
Amnesty International's report has gathered information on abductions and attacks such as beatings and torture meted out to activists, protesters and journalists as Kiev lost its hold over the region.
A soldier looking out from an armoured vehicle in eastern Ukraine "With hundreds abducted over the last three months, the time has come to take stock of what has happened, and stop this abhorrent ongoing practice," said Amnesty's Denis Krivosheev.
There are no comprehensive or reliable figures for the number of abductions - Ukraine itself says there were nearly 500 cases between April and June 2014 but the UN Human Rights Monitoring Mission for Ukraine says it recorded 222 cases of abductions in the last three months.
Amnesty says most are being carried out by armed separatists, with the victims often subjected to beatings and torture. But it says there is also evidence of a smaller number of abuses by pro-Kiev forces.
A pro-Russian separatist in the eastern town of Donetsk It says abductions have taken place across eastern Ukraine in the Donetsk and Luhansk regions.
"Now that pro-Kiev forces are re-establishing control over Slavyansk, Kramatorsk and various other places in eastern Ukraine, new captives are being released almost daily with an increasing number of disturbing cases emerging," said Mr Krivosheev..
"It is time that these are meticulously documented with perpetrators brought to justice with victims awarded compensation."
Hanna, a pro-Ukrainian activist, told Amnesty International how she was abducted by armed men in the eastern city of Donetsk on May 27.
Ukraine troops took control of Slavyansk She said she was held for six days before being released in a prisoner exchange. She described how she was violently interrogated.
"My face was smashed, he punched me in the face with his fist, he was trying to beat me everywhere, I was covering myself with my hands … I was huddled in the corner, curled up in a ball with my hands around my knees. He was angry that I was trying to protect myself. He went out and came back with a knife."
Hanna showed scars on her neck, arms and legs where she says she was sliced with the blade: there is a stab wound in her knee, her right index finger is still heavily bandaged in a plastic splint.
The eastern town was badly shelled last week She also described how her interrogator made her write a separatist slogan on the wall, in her own blood.
While most abductions appear to have a "political" motivation, there is clear evidence that abduction and torture is being used by armed groups to exert fear and control over local populations. People have also being abducted for ransom.
Sasha, a 19-year-old pro-Ukrainian activist, fled to Kiev after he was abducted by separatists at gunpoint in Luhansk. He said he was beaten repeatedly for 24 hours.
President Poroshenko was elected in May "They beat me with their fists, a chair, anything they could find. They stubbed out cigarettes on my leg and electrocuted me. It went on for so long, I couldn't feel anything anymore, I just passed out," he said.
He was finally released after his father paid a $60,000 ransom (£35,010).
There are allegations of atrocities on both sides.
One local government official in Mariupol, who wished to remain anonymous, told Amnesty International how they heard a captive separatist fighter wailing in pain at the hands of pro-Kiev forces who were seemingly trying to extract information about the separatists.
The report was published as Ukrainian officials said a missile attack in by pro-separatist fighters may have killed at least 30 soldiers and border guards, with final figures possibly even higher.
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