A photograher and three members of the feminist movement Femen known for their bare-breasted protests were illegally held in police custody overnight after being abducted by unknown assailants during Vladimir Putin's visit to Ukraine, the group said Sunday.
Police denied the four were snatched off the streets of the Ukranian capital Kiev in broad daylight Saturday.
A police spokesman said they were detained when the topless women with slogans daubed on their bodies violated orders by posing for the photographer in a public place.
The Ukrainian activists are now facing charges of petty hooliganism, while the photographer is accused of defying police orders.
The four, who are facing a fine and up to 15 days in jail, were taken to a court for a closed-door hearing Sunday.
Femen said Oksana Shachko, Oleksandra Shevchenko, Yana Zhdanova and Dmitry Kostyukov were allegedly beaten up, bundled into a car and spirited away by unknown men ahead of their planned protest against Putin's visit.
Femen calls Putin and Russian Orthodox Patriarch Kirill, who is accompanying the leader to Ukraine, the "enemies of democracy and freedom" and have heckled both in the past.
The group's lawyer Yaroslav Yatsenko said the three activists and the photographer were taken to a police station after being snatched off the street and had to spend the night in custody.
He said Kostyukov and Shachko were beaten so badly that they were briefly hospitalised.
"Dmitry was kicked and received a head injury," he said, referring to Kostyukov, who is a former AFP photographer and holds a Russian passport.
Yatsenko said the four had been held in custody overnight illegally.
A Femen activist who witnessed the attack from her apartment window said the activists were emerging from an apartment building when a group of five or six men charged at them.
"They were wearing civilian clothes," Yevhenia Kraizman told AFP.
The attack followed an alleged assault earlier Saturday on the group's leader Anna Hutsol which she described as a warning by Ukranian special services not to stage any protests during Putin's two-day visit.
Putin on Saturday joined his Ukrainian host Viktor Yanukovych for politically sensitive celebrations of the 1025th anniversary of the arrival of Christianity in Russia and Ukraine.
Serbian leader Tomislav Nicolic and Moldovan President Nicolae Timofti were also in attendance.
On Saturday morning Hutsol was hit in the face in her apartment building by an unknown man who grabbed her dog and ran away.
After the activists went missing, Hutsol was Saturday night again attacked by a stranger who she said hit her in the face at a cafe and made off with her notebook.
"I am outraged that they are now attacking people in public places," said Hutsol whose right eye was badly bruised.
Saturday's attacks come after a leading male activist with the group, Viktor Svyatskiy, was brutally beaten up last Wednesday.
Femen's female activists have become well-known in Ukraine and abroad for baring their breasts to protest discrimination against women and other rights violations.
The group blamed the latest attacks on the Ukrainian and Russian special services.
A spokeswoman for the Ukrainian Security Service (SBU), Lada Safonova, said the service did not target Femen.
"We are not conducting any investigative work with regards to this organisation," she told AFP, adding that the SBU was busy Saturday ensuring the safety of the leaders.
In 2011, three Femen feminists who staged a topless protest mocking Belarussian leader Alexander Lukashenko were kidnapped in Belarus by local security services who forced the women to stip naked in a forest, the group has said.
One of those activists was this month granted political asylum in France.
Putin and Yanukovych were on Sunday in the Ukrainian port of Sevastopol where they celebrated Navy Day and inspected battleships of the two countries.