Updated

Police on Friday opened an investigation into the kidnapping of an opposition activist, who said he was held captive for more than a week and tortured in the latest in a string of mysterious attacks on anti-government protesters in the two-month-long political crisis.

Dmytro Bulatov, 35, a member of Automaidan, a group of car owners that has taken part in the protests against President Viktor Yanukovych, went missing Jan. 22.

Bulatov was discovered outside Kiev on Thursday. He said his kidnappers beat him severely, drove nails into his hands, sliced off a piece of ear and cut his face. He said he was kept in the dark all the time and could not identify the kidnappers. After more than a week of beatings, they eventually dumped him in a forest.

"They crucified me, they nailed down my hands. They cut off my ear, they cut my face. There isn't a spot on my body that hasn't been beaten," Bulatov said on Channel 5 television. "Thank God, I am alive."

Bulatov's face and clothes were covered in clotted blood, his hands were swollen and bore the marks of nails.

Opposition leader Petro Poroshenko rushed to the hospital where Bulatov was taken Thursday night.

"Dmytro asked to pass his greetings to everyone and to say that he has not been broken and will not be broken," a grim-looking Poroshenko told Channel 5. "That he is full of energy and despite the fact that his body has been beaten, Dmytro's spirit is strong."

Police said the car he was driving when he disappeared had been found.

Bulatov had been missing for eight days, and the protesters organized a campaign for his release. They pleaded with top government officials for assistance, offered a $25,000 bounty to anyone who could help locate him and even consulted psychics, said Oleksiy Hrytsenko, Bulatov's friend and fellow activist.

Hrytsenko said Automaidan members had come under tremendous pressure during the protests, with their cars burnt and activists detained, harassed and threatened. He showed an Associated Press reporter a text message he had received from an unknown number that read: "Go ahead, go ahead, your mother will be happy to see her son dead."

The AP was not immediately able to interview Bulatov.

He is among three activists whose disappearances have shocked the country, especially after one of them was found dead.

Bulatov went missing one day after Igor Lutsenko, another prominent opposition activist who had also gone missing, was discovered after being taken to the woods and beaten severely by unknown attackers.

Lutsenko was kidnapped from a hospital, where he had brought a fellow protester, Yuri Verbitsky, to be treated for an eye injury. Verbitsky was also beaten severely and was later discovered dead.

The disappearances prompted an outcry from protesters, who accused the government of intimidating the opposition.

European Union foreign policy chief Catherine Ashton issued a statement saying she was "appalled by the obvious signs of prolonged torture and cruel treatment" of Bulatov. She also condemned the death of Verbitsky.

"These are but two cases of the continuous deliberate targeting of organizers and participants of peaceful protests," Ashton said. "All such acts are unacceptable and must immediately be stopped. It is the authorities' responsibility to take all necessary measures to address the current atmosphere of intimidation and impunity which allows for such acts to take place. All unlawfully detained people have to be released and perpetrators brought to justice."

The protests started after Yanukovych backed out of an agreement to deepen ties with the European Union in November, but quickly came to encompass an array of discontent over corruption, heavy-handed police and dubious courts.

Negotiations between the authorities and the opposition on finding a way out of the crisis appeared to have stalled on Thursday, after Yanukovych took an unexpected sick leave and told opposition leaders that it was now up to them to make concessions.

This week Yanukovych accepted the resignation of Prime Minister Mykola Azarov and the parliament, which he controls, and rescinded harsh anti-protest legislation that sparked last week's violence.

Yanukovych's allies in parliament also passed a bill offering to grant amnesty to protesters, but only after they vacate scores of government buildings they have seized across the country. Yanukovych signed the bill into law on Friday, but the opposition has rejected the offe, saying it amounts to Yanukovych taking demonstrators as hostages. It has insisted that protesters must be freed without any conditions.