THESSALONIKI, Greece (AP) — Police in northeastern Greece say they are investigating the killing of seven puppies that were found dumped on the side of a road with their heads cut off.

Residents in the village of Lambro, outside the northeast city of Komotini, reported the incident late last week, and a formal investigation was opened by police on Monday.

Lambro resident Ali Mesut told The Associated Press: "The whole village is upset about what happened. I hope they catch who did this."

Greek animal protection groups say attacks on stray dogs — mostly using poison — are common in the area.

Earlier this year, Greek lawmakers toughened penalties for cruelty toward animals.