Poisoning is suspected in the deaths of 18 wolves within a few days in a national park that straddles three regions of central Italy.

After the carcasses of 10 wolves were found last week, another eight were found when patrols were stepped up in recent days in the Abruzzo, Lazio, and Molise National Park.

The park authority said last week that traces of suspected poisoned bait had been found in an area where five of the wolves had been found dead and the latest deaths elsewhere raised "very strong suspicion" of further poisoning.

The authority said it was working to determine the cause of death and collaborating with local public prosecutors.

The park's initial suspicions appear to have been corroborated in tests carried out by the local animal health research institute IZS.

Thirteen of the dead wolves were taken to the institute in Teramo, which found the "presence of pesticides for agriculture used in poisoned bait for animals".

In a sign of the national seriousness of the issue, Environment Minister Gilberto Pichetto Fratin also intervened, condemning the killings as "horrendous and serious", adding that the protection of wolves was "crucial to the balance of our ecosystem".

Italy's Institute for Environmental Protection and Research (Ispra) warned that the killing of wolves most likely by poisoning called into question significant advances in animal protection and conservation.

Poisoned bait posed a concrete risk to other protected wild species as well as domestic pets and public safety, it said.

Wolves have seen their population swell in Europe in recent years, with the European Union reporting a 35% increase to 23,000 from 2016 to 2023, concentrated especially in Central Europe and Alpine regions.

In Italy alone the wolf population was estimated to be about 3,300, according to a 2020-21 census by Ispra.

Accompanying that rise has been an increase in attacks on livestock, and that has led to the EU downgrading the "strictly protected" status of wolves to "protected". Latest EU data suggests 65,500 individual livestock are killed by wolves each year.

The change of status to merely "protected" has paved the way for a limited cull of 160 wolves to be allowed in Italy annually from 2026, but wildlife groups have appealed for that to be revisited in the wake of the suspected poisonings.

The head of environmental group Legambiente, Stefano Ciafani, described the 18 deaths as an "unprecedented attack on protected wildlife" and an example of "do-it-yourself justice".

He warned that other animals could now come under attack, including the Marsican brown bear - a critically endangered species considered a symbol of the Abruzzo national park. About 50 Marsican bears remain.