To me this sounds very much like an attempt by the local authorities to protect their tourist industry by trying to cover up that there is a real danger from the packs of stray dogs in the region, and to shift the blame onto a wild animal, either wolves or jackals. At the same time, this will presumably give the local people more 'justification' to go shoot and/or poison the local carnivores.
For many years I have been involved with carnivore research in the Rodopi Mountains, mainly across the border in Bulgaria, but of course with a great interest in what is happening on the southern slopes of the range in Greece. I would be very interested to see any research evidence that confirms the presence of wolf packs south of the E90 motorway along the coastal strip in which the village and archaeological site of Maroneia lies. I have my doubts.
As far as I am aware, this coastal strip is home to Greece's largest population of Golden Jackal, but I have seen no data indicating that these animals are involved in any major depredation on livestock in the region, and certainly no cases of aggression towards people. There have been a number of jackal attacks on humans in Asia, but most of these have been rabid animals, or occasionally starving animals. Furthermore, packs of jackals almost always hunt by night, not during the day.
I would, therefore, be extremely surprised if either wolf or jackal were to blame in this case. Unfortunately, even the suggestion that they 'may' be to blame, is likely to be enough to cause an increase in carnivore persecution in the region!