Turkish President Tayyip Erdogan said on Wednesday that Israel’s blockade and bombing of Gaza in retaliation for Palestinian militant group Hamas’ attack was a disproportionate response amounting to a “massacre”.

With Ankara offering to mediate, Erdogan and his foreign minister held calls with regional powers, the United States and others. However, Israel’s envoy to Ankara has said it is too early to discuss mediation.

Speaking to his ruling AK Party in parliament, Erdogan said even war had a “morality” but the flare-up since the weekend had “very severely” violated that.

“Preventing people meeting their most fundamental needs and bombing housing where civilians live – in short, conducting a conflict using every sort of shameful method – is not a war, it’s a massacre,” he said, referring to Israel cutting off electricity and water to Gaza and destroying infrastructure.

Turkey, which has backed Palestinians in the past and hosted members of Hamas, has been working to mend ties with Israel after years of animosity. Unlike the European Union and U.S., Ankara does not consider Hamas a terrorist organisation.

While not openly blaming Israel, Turkey has said the fighting is due to years of injustices against Palestinians and that the only path to peace is the formation of a sovereign Palestinian state in a two-state solution.

On Wednesday, Erdogan criticised Israel’s “disproportionate” attacks on Gaza as “devoid of any ethical foundation”, and called on the world not to “blindly” take one side. Leaving the underlying issue unresolved would lead to new, more violent conflicts, he warned.

“We call on countries in the Americas, Europe, and other regions to take up a position between the parties that is fair, just, and based on humanitarian balances. Everyone should refrain from acts that will wholly punish the Palestinian people, like blocking humanitarian aid,” he said