Swiss banker Josef Ackermann – the head of Germany’s biggest bank – was the target of a letter bomb, agencies reported on Thursday.

Initial investigations showed the device was a viable bomb and could have caused serious injury, according to the Frankfurt prosecutor’s office and Hessen criminal office.

Frankfurt police earlier said the bomb was home made.

An Italian anarchist group has claimed responsibility for the letter bomb, and may have sent two more packages, investigators added on Thursday. 
                                   
The suspicious envelope, intercepted on Wednesday evening, has raised fears that a wave of protests against the failures and excesses of bankers could turn more violent, and prompted police across Europe to warn banks to be extra vigilant. 
                                   
Ackermann, the first non-German to head Germany's biggest bank, is one of the few senior managers in the country always surrounded by bodyguards. 
                                   
A hidden, rolled-up letter written in Italian from the Federazione Anarchica Informale (the Informal Anarchist Group, or FAI) spoke of "three explosions against bankers, banks, fleas and bloodsuckers", the German investigators said. 

The letter containing the explosive was addressed personally to the 63-year-old banker and discovered by Deutsche Bank security staff during routine checks of post.

Reports say Ackermann is a controversial figure in Germany, who is criticised by sectors of the German public for his uncompromising support for the finance industry.

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