By James Rodgers
BBC News
**The Ukrainian and Russian authorities have publicly accused each other of spying.**Ukraine said it had expelled four Russians and detained another on suspicion of espionage.
Russia’s FSB security service confirmed the incident but said its actions were a response to Ukrainian espionage.
Ukraine’s relations with its former Soviet master have been strained in recent months but two weeks ago Russia returned an ambassador to Kiev.
The row comes days before the second and decisive round of Ukraine’s presidential election, in which relations with Russia are an issue.
Sensitive time
Ukraine said that the five alleged Russian spies were caught possessing a camera concealed inside a pen, other espionage equipment and $2,000 (£1,250) - a reported bribe for a Ukrainian contact.
The head of Ukraine’s security service says that the five were trying to obtain military secrets.
The FSB said its actions were a response to the recruitment of Russians by the Ukrainian security services.
The accusations come at a highly sensitive time.
The mutual recriminations also come just two weeks after Russia returned an ambassador to Ukraine, ending a five-month diplomatic rift.
And on Sunday, Ukrainians will vote in an election to choose a successor to outgoing President Viktor Yushchenko.
Mr Yushchenko’s time in office has been marked by strained relations with Moscow, and his departure was being seen as an opportunity for an improvement in ties between the two countries.