In a tit-for-tat move, Romania declared a top Russian diplomat in Bucharest persona non grata on Tuesday and ordered him to leave the country in 48 hours.

On Monday, Russia's Federal Security Service (FSB) announced that Gabriel Grecu, first secretary of the political department of the Romanian Embassy in Moscow, had been detained in Moscow while trying to obtain military secrets from a Russian national.

Romanian diplomat Gabriel Grecu, arrested on Monday in Moscow, accused of espionage, tried to obtain secret military data, according to a press release of the Russian secret services, FSB, quoted by Ria Novosti. Grecu was detained on Monday, in Moscow, after a set up organized by the secret services.

According to information offered by FSB, Grecu's predecessor, who left the Russian capital city in 2008 tried to obtain analytical information about Moldova and Transniester and compromising information about leaders and political men in Transniester.

Romanian diplomat Grecu was detained in Moscow, accused of espinage and the Russian secret services declared that they found on Grecu objects specific to espionage activities.

According to the information released by the Russian secret services, Grecu was working undercover, as first secretary of the political department of the Embassy of Romania to Moscow.

Grecu was quickly declared persona non grata and ordered to leave the country within 48 hours.

Romania's Foreign Ministry said the Russian diplomat had "equivalent ranking" to Grecu - i.e., first secretary, but did not release any names.

There has been no comment from Moscow yet.