London — Prince William condemned antisemitism during a visit to a London synagogue on Thursday, the first time he appeared in public after unexpectedly pulling out of a royal event earlier in the week. William’s bailing on the memorial event for his late godfather fueled speculation over the royal family’s vague assurances that both William’s father King Charles III, and his wife Kate, the Princess of Wales, continue to do well amid health problems.

The royal said he and Kate were extremely concerned about the rise in antisemitism. “I’m here today to reassure you all that people do care, people do listen and we can’t let that keep going,” he said.

William’s absence on Tuesday from the memorial service for his godfather, the late King Constantine of Greece, drew significant media attention because it came as King Charles undergoes treatment for an unspecified cancer and Kate recovers from abdominal surgery for an also unspecified condition.

Palace officials said only that William had pulled out of the service at Windsor because of a “personal matter.” They declined to elaborate, but said his wife continued to do well as she recovers from her surgery.

The nature of the future queen’s medical procedure has not been revealed, but she returned home to continue her recovery after about a week and a half in a private London hospital at the end of January. Kensington Palace has said she’s expected to return to her public duties around the end of March.

King Charles has canceled all public engagements as he undergoes periodic treatments for cancer.

While it is understood that William’s absence from Tuesday’s memorial service was not related to his father’s illness, the palace said only that Kate was still recovering well, without providing any further information about the nature of the personal matter that kept the prince away from the family event.

Before his visit to the synagogue, William spoke out last week against the fighting in Gaza and called for the Israel-Hamas conflict to end “as soon as possible.”

While his statement stopped short of calling for an immediate cease-fire in Gaza, he spoke of the “terrible human cost of the conflict in the Middle East since the Hamas terrorist attack” and urged more humanitarian support for civilians in Gaza.

William heard Thursday about how Jewish students across the U.K. have been affected by the rise of hatred against the Jewish community during his visit to the Western Marble Arch Synagogue. He also spent time with Renee Salt, a 94-year-old Holocaust survivor.

Reports of both antisemitic and anti-Muslim abuse in Britain have soared since Hamas’ Oct. 7 attack on Israel, which triggered Israel’s invasion of Gaza.