The strikes constitute a "dangerous escalation which threatens to bring serious consequences for the stability of the region", said the statement from Egypt, which brokered the Gaza ceasefire alongside Qatar and the United States.

It called on the international community to "act immediately to halt the Israeli aggression against the Gaza Strip in order to prevent the region entering a new spiral of violence and counterviolence".

Israel's overnight strikes, which the health ministry in Hamas-run Gaza said killed more than 330 people, were by far the biggest since the ceasefire. Hamas has not responded to them so far.