BERLIN (AP) — German officials said Monday they have secured a suspicious package delivered to a state governor's office and were investigating it for possible explosives.

Thuringia governor Bodo Ramelow told the dpa news agency that police were alerted by workers in the office in Erfurt and have told him the package may contain a hand grenade.

Thuringia governor's office spokesman Guenter Kolodziej told The Associated Press that a police bomb squad was inspecting the package. He didn't give any further details.

Another suspicious package was delivered Friday to a pharmacy in Potsdam, triggering the evacuation of a Christmas market on the same street, after police were called.

Security officials have said that package was part of a conspiracy to extort millions of euros (dollars) from delivery company DHL. An online company in Frankfurt an der Oder received a similar package at the beginning of last month which started burning when it was opened, they said.

The sender or senders have threatened to continue sending more dangerous packages if they don't receive millions from the delivery company. DHL wasn't immediately available for comment Monday, and declined to comment to dpa on Sunday.

The package found in Erfurt was also delivered by DHL. Authorities declined to say whether they had any clues about the sender's identity.

It was delivered Friday, like the Potsdam package, but initially put on a shelf. Employees only looked at it Monday.

Ramelow said it was "pure speculation" at the moment whether the Erfurt incident was related to the Potsdam package.

However, officials in Brandenburg state, where Potsdam is located, have said that further attempts to extort money from other companies or private individuals are likely. That state's interior minister advised people Sunday not to open suspicious packages because they might explode.

Police initially said the package sent to the Potsdam pharmacist contained "a cylindrical object with cables, batteries and nails" but lacked an ignition mechanism and wasn't viable as a bomb. They later said it could have exploded, though didn't elaborate on how.

Along with the device, the package held a letter that directed investigators to an online message outlining a blackmail plot and mentioning the parcel delivered to Frankfurt an der Oder, also in Brandenburg.