VATICAN CITY -- The lights went out atop St. Peter's Basilica, robbing the Rome skyline of one of its most evocative images and leaving tourists wondering if Vatican City had suffered a blackout. Utility company officials said Monday that a computer problem and not a power shortage was to blame.

The dome and facade of the basilica went dark Sunday night, but other lights at the Vatican stayed on, including the illumination of Bernini's colonnade around St. Peter's Square.

After the basilica was scrubbed clean of centuries of grime for the Vatican's millennium celebrations in 2000, Rome's electric company, ACEA, provided 18 large lights to illuminate the cupola, atrium and facade.

ACEA officials said they were told that the lights didn't go on because of a computer reset problem at the Vatican.

The Vatican's press office declined to talk about the incident.

Pope John Paul II and much of the papal household have been spending the last few hot weeks at the pontiff's summer residence in Castel Gandolfo in the cooler Alban hills southeast of Rome.