Berlin: The German foreign ministry warned on Wednesday about possible attacks on Istanbul’s underground rail network and bus stops in the wake of Turkey’s assault on Kurdish militants in northern Iraq.

‘There could be increased attack activity by the PKK,’ the foreign ministry said in a statement on its website, referring to the Kurdistan Workers Party.

‘Beyond that there are indications of possible attacks on the underground rail network and bus stops in Istanbul,’ the ministry added.

The number of foreign visitors to Turkey fell by 2.25% to 14.89 million people in the first six months, data from the Tourism Ministry showed on Wednesday.