The German Federal Prosecutor's office said Friday that three foreign nationals had been arrested on suspicion of working for a foreign secret service.     

The three accused were said to have traveled to Germany on behalf of a foreign secret service to collect information on a person from Ukraine who was staying in the country.

What we know so far

Hesse state police arrested the three men in the German financial hub of Frankfurt am Main and applications for arrest warrants were submitted to an investigating judge. The three appeared in court on Thursday to be placed in custody ahead of a possible indictment.

The three were said to have scouted out a cafe in the German financial hub of Frankfurt am Main, where the target individual was believed to be.

Prosecutors named the three only as Ukrainian national Robert A., Armenian national Vardges I., and Russian national Arman S. Their full names weren't released in line with German press and privacy rules.

Series of espionage arrests

A string of spying cases in Germany, involving alleged Russian and Chinese agents, have garnered widespread attention. 

Two Russian-German dual nationals were arrested in April for allegedly scouting potential sabotage targets on German soil.

Meanwhile, a top-ranking officer in Germany's foreign intelligence agency (BND) remains on trial in Berlin on charges of treason for allegedly passing top secret information to Russian spies with the help of a co-defendant.

An employee of the German European Parliament lawmaker Maximilian Krah, a member of the far-right Alternative for Germany (AfD) was arrested in April on suspicion of spying for China.

Also in April, three suspected spies who wereallegedly working for China were arrested in Germany. The group was accused of seeking to gather sensitive information about German military technology through a front company.

rc/lo (AFP, Reuters)