LONDON (AP) — Buckingham Palace says Princess Anne has sustained minor injuries and a concussion following an incident on an estate in southwest England.

The 73-year-old sister of King Charles III has been hospitalized as a precautionary measure for observation and is expected to make a full recovery.

The palace said the incident happened on Sunday on the Gatcombe Park estate.

It did not offer details.

Britain’s Press Association reported that the princess was walking within the protected perimeter of the estate when the incident occurred.

Though the exact cause of the injuries is unconfirmed, there were horses in the area.