KIEV (Reuters) - One of the international observers being held by pro-Russian separatists in the eastern Ukrainian city of Slaviansk needs urgent medical care, Ukraine's state security service said on Saturday.
"Today the official representatives of the OSCE (Organisation for Security and Cooperation in Europe) are being held in inhuman conditions," the service said in a statement on its Internet site. "Among those detained is a person who needs immediate medical help."
The statement said Ukrainian security services were ready to provide medical assistance, but the separatists had rejected this offer. "The terrorists plan to use the hostages as a human shield," the statement said.
It said the detention of the observers was planned and coordinated by a Russian citizen who Kiev says is a Russian special service operative. Russia denies that it has any of its troops or agents in eastern Ukraine.
Meanwhile, Czech Prime Minister Bohuslav Sobotka called on Saturday for an immediate release of the group of observers.
"The Czech Republic condemns the detention of international observers...calls for their immediate release," Mr Sobotka said in a statement.
The German-led monitoring mission, made up of eight international observers including a Czech national, was detained in the city of Slaviansk on Friday.