According to a report published by the Russian Interfax news agency the group of OSCE observers who are being detained by Russian separatists in the town of Slaviansk, in eastern Ukraine, are unharmed and are being treated as “guests”. The town’s pro-Russian mayor Vjacheslav Ponomarjov confirmed on Monday that an offer had been made to exchange them for Russian separatists held in Kiev. According to the Czech ambassador to Kiev, the negotiations are complicated and the Ukrainian government has not yet responded to the offer. The Ukrainian Intelligence Service says it has evidence that the operation in which OSCE observers were taken hostage was masterminded by the Russian military intelligence. Among the captives are German, Czech, Polish and Danish nationals. A Swede who suffers from diabetes was released on Sunday.