A French tourist died from head injuries and her husband was hospitalised after being attacked by an "unstable" man near Rabat, a hospital official and Moroccan authorities said Monday.
"The woman, born in 1940, is unfortunately deceased. She arrived at the hospital already dead," Dr. Leila Derfoufi of Moulay Youssef Hospital told AFP.
"We are very disappointed that we could not save her."
Her husband, also in his eighties, is in "stable condition", the doctor added.
The couple was attacked by an "unstable person" Monday in the coastal town of Moulay Bousselham, not far from Morocco's capital, authorities said.
He "attacked the two tourists for no apparent reason with stones, causing them injuries of varying severities", they said, adding that the man was arrested and taken into custody by the local gendarmerie.
An investigation into the attack is ongoing.
Monday's attack comes two days before the semi-final of the World Cup between Morocco and its former colonial power France.
The French make up the largest number of tourists visiting Morocco.
In January, a 79-year-old French tourist was killed by an attacker with a knife in a market in the southern Moroccan city of Tiznit.
A court ruled that the perpetrator was not criminally responsible due to "mental disorders" and called for their internment in a psychiatric hospital.