BERLIN (AP) — Berlin police say threatening letters containing a white powder have been sent to both the American and Israeli embassies in the German capital.

Police spokeswoman Kerstin Ismer told The Associated Press on Tuesday that the Israeli Embassy received a letter July 24 and the U.S. Embassy on July 26. Ismer says police have opened two investigations on suspicion of disturbing the peace by threatening a crime.

She says both contained a powder but would not comment on whether it had been determined to be dangerous or other details due to the ongoing investigation. She would also not say whether the two letters were thought to be connected or whether there were any suspects yet.

Neither embassy had any immediate comment, saying in general they do not comment on security issues.