BERLIN (AP) — Germany says China should give U.N. human rights officials unhindered access to camps in its western region of Xinjiang, after leaked documents indicated they are used to forcibly re-educate minorities.

Foreign Ministry spokeswoman Maria Adebahr on Monday said Germany was “following with great concern” recent news reports about the camps, where about 1 million people are being held.

Government spokesman Steffen Seibert said Germany has previously joined other countries in calling for U.N. experts to be allowed to visit the camps and produce an independent assessment of the situation there.

Seibert told reporters in Berlin that “we must now concentrate on verifying these reports.”

China’s embassy in the United Kingdom has said the documents, which were leaked to a consortium of international journalists, “are fabrication and fake news.”