Berlin (Reuters) - Five top German politicians received envelopes on Thursday that contained threatening letters and a white powder the letters said was anthrax, which turned out to be harmless, Berlin police said.

Chancellor Angela Merkel reportedly received one of the letters, the broadcaster ARD said on its website, but the police spokesman did not confirm that.

Special security forces were deployed to investigate the incident, a spokesman for the Berlin State Criminal Police office said, confirming news that was first reported ARD.

Horst Seehofer, who heads the Bavarian sister party of Merkel’s conservatives, told journalists he had received one of the letters.

ARD said the other letters went to Katrin Goering-Eckardt and Hans-Christian Stroebele, members of the pro-environment Greens party, and Gregor Gysi, former chief of the left-wing Left party. Stroebele confirmed the incident in a posting on Twitter.

He told ARD that the letter was probably sent by right-wing extremists, even though it was written in Arabic. He gave no explanation.

A photograph of the letter included the phrases “Salafist community, Germany” and “Lethal, Do not touch, Dangerous, Caution” - all in typewritten Arabic characters.