Charles is extremely concerned over the situation and is being actively briefed on developments while William and Kate were described as being “profoundly distressed” at the “devastating” events.
The senior royals offered their thoughts and prayers to all those suffering, with the King doing so personally in a telephone call to President Isaac Herzog on Wednesday afternoon.
Kensington Palace shared William and Kate’s reaction to the attacks, saying: “The Prince and Princess of Wales are profoundly distressed by the devastating events that have unfolded in the past days.
“The horrors inflicted by Hamas’s terrorist attack upon Israel are appalling; they utterly condemn them.”
They added that the couple were holding “all the victims, their families and their friends in their hearts and minds”.
Israel has vowed unprecedented retaliation against the Palestinian militant group Hamas after its fighters stormed through the border fence on Saturday and shot hundreds of Israelis in their homes, on the streets and at an outdoor music festival.
The Israeli government has launched a major retaliation of air strikes on Gaza and stopped the passage of food, water, fuel and medicine into the territory.
The conflict has already claimed at least 2,200 lives on both sides, with fears it could escalate further.
Concerns also remain for the safety of British citizens in the region as the BBC reported that 17 UK nationals are either dead or missing, including children.
The King also spoke with King Abdullah of Jordan, whose nation shares a border with the West Bank and is home to a large number of Palestinian refugees.
King Abdullah has been striving to de-escalate the situation. Charles, who long campaigned on interfaith tolerance as the Prince of Wales, is said to be continuing to seek ways to do so amid the growing conflict.
A Buckingham Palace spokesman said: “This is a situation His Majesty is extremely concerned about and he has asked to be kept actively updated.
“His thoughts and prayers are with all of those suffering, particularly those who have lost loved ones, but also those actively involved as we speak.”
He added: “His Majesty is appalled by and condemns the barbaric acts of terrorism in Israel.”
Charles, as the Prince of Wales, carried out his first official tour of Israel and the Occupied Palestinian Territories in 2020.
It was the highest-level visit by a member of the monarchy to Israel and the Palestinian areas.
William also travelled there in 2018, and he and Kate have signified their hopes of peace in the future.
The Kensington Palace spokesperson said: “Those the Prince of Wales met in 2018 overwhelmingly shared a common hope – that of a better future.
“In the midst of such terrible suffering, the prince and princess continue to share that hope without reservation.”
They also expressed sympathy for both Israelis and Palestinians, with the Palace spokesperson saying: “As Israel exercises its right of self defence, all Israelis and Palestinians will continue to be stalked by grief, fear and anger in the time to come.”