“It has been 45 days since three members and employees of Gruenhelme were kidnapped overnight on May 14-15, in the village of Harem” of Idlib, the group’s founder Rupert Neudeck said in a statement on June 28.

The three members have been identified as Bernd Blechschmidt, Simon S. and Ziad Nouri.

Neudeck added that Gruenhelme (Green Helmets) has asked the German Foreign Ministry, German police, and the Syrian opposition in Germany for help, but the identity of the kidnappers has not been clarified yet.

The German Foreign Ministry confirmed that three German nationals have been “reported missing” in Syria, without giving further details.

Neudeck said his group was “very surprised to see that… the media in Germany have been silent” on the issue.

“But we are no longer able to remain silent,” he said.

The aid group has been active in northern Syria for several months to help provide healthcare to local people.

Syria has been gripped by a deadly unrest since March 2011, and many people, including large numbers of Syrian forces, have been killed in the violence.

Foreign-sponsored militants have committed major crimes in the country including kidnapping Syrians and foreigners.

In April, the militants released two Orthodox archbishops kidnapped in the northwestern city of Aleppo.

Several international human rights organizations have also accused militants operating in Syria of committing war crimes.