ROME -- After days of controversy over accusations of obscenity and blasphemy by Italian Catholic groups, rock star Madonna opened the Italian portion of her "Blond Ambition" world tour here this week with a concert that drew only about two-thirds the capacity of the 32,000-seat Flaminio Stadium.

It was difficult to say what role the Catholic protests played in the low turnout, but Madonna had to cancel a second show because of slow ticket sales.

Several Catholic groups and the news service of the Italian bishops' conference had sharply criticized the show in advance and called for its cancellation, apparently based on reviews of earlier European performances that described the singer's combined onstage use of Christian symbols and simulated sex.

The latest protest came from a group called The Committee of Catholic Families in the northern city of Turin, which sent a letter to the mayor and telegrams to the concert sponsors calling the show "disgusting, immoral, blasphemous and infamous."

In contrast, the Catholic-oriented Friends of Entertainment group in Pacentro -- the town where Madonna Ciccione's family originated -- sent a telegram expressing "full disapproval and concern for the crusade against Madonna."

On arriving in Italy Monday, Madonna read a statement giving a spirited defense of her show and free expression. She urged Catholics to see the performance before judging it and advised, "If you are sure that I am a sinner, let he who is without sin cast the first stone."

Madonna also warned that if someone opposes freedom of expression, "you imprison everyone's mind, and when the mind is imprisoned, our spiritual life dies."

The Madonna controversy came simultaneously with another row in Italy over accusations of blasphemy in art.

Following protests from residents in the town of Andora, a collage of photographs of a nude woman that were arranged in the form of a cross was removed from an art exhibition in a church there by order of Bishop Alessandro Piazza.

The medieval church is rarely used for religious services. Although it belongs to the town, it is still consecrated, and because of this the bishop said he had final jurisdiction over what was displayed in it.