"The German army has suspended the training," defence ministry spokesman Jens Flosdorff said, adding that there was "generally heightened alert, awareness" for soldiers currently operating in the region.

Flosdorff said training may resume in the next few days and that there was "no concrete threat" at the moment.

Germany has about 160 soldiers deployed in Iraq, including 60 in Taji, just to the north of Baghdad, and 100 in Erbil, in Kurdish-controlled northern territory.

Separately, the Netherlands' defence ministry said it was also suspending its training mission in Iraq due to "threats", the Dutch ANP news agency said.

More than 50 Dutch soldiers are training Kurdish troops in Erbil in the context of the international coalition against the Islamic State group, ANP said.

The defence ministry website says the Netherlands also supplies two military advisers and four civilian experts to the NATO "capacity-building mission" in Baghdad.

Lithuania, which has eight soldiers in Iraq, said it did not plan to halt its mission.