In a move that is likely to add further speculation about the nature of the sites targeted, Russia’s Foreign Ministry is publicly demanding an explanation from Israel as to why they attacked targets inside Syria on Sunday.

Israel attacked around 10 sites, mostly around the Damascus Airport, and while it’s unclear what was hit, some reports suggested it included Russian anti-aircraft defenses which were being provided to Syria.

Syria and Iran both condemned the Israeli attacks too, but those are unsurprising, and Russia normally doesn’t get directly involved in Israel’s intermittent attacks on Syria.

The Russian Foreign Ministry also pushed the UN Secretary-General Ban Ki-moon over the attack, urging him to take steps to ensure that such attacks are not repeated.

Israel, for its part, is refusing to confirm or deny the attacks, nor is it offering any explanation for what it attacked, or why. They attack Syria fairly often, so from their perspective it might not be seen as worth responding to.