Pope Benedict XVI marked the fifth anniversary of his election Monday under the shadow of a clerical sex abuse scandal that has plunged the Catholic Church into its most serious crisis of recent times.

Benedict was the host of a lunch at the Vatican with about 60 cardinals, and they cheered and applauded him.

Sitting next to the pontiff in the ornate Apostolic Palace were two of his closest aides, Cardinal Tarcisio Bertone, the Vatican's secretary of state, and Cardinal Angelo Sodano, dean of the College of Cardinals and one of the pope's most ardent defenders in the face of the scandal.

The pope leads the church "with great generosity" in the face of "the challenges that the modern world poses to each disciple of Christ," Sodano said in an address to the pontiff, according to Vatican Radio.

Benedict has just returned from a two-day pilgrimage to Malta, where he met privately with abuse victims.

As part of the anniversary celebrations, the Italian bishops' conference has invited faithful in churches across Italy to pray for Benedict. The conference also invited the faithful to remember in their prayers both "the victims of sex abuse and those who have stained themselves with such heinous crimes."

Reports of abuse of minors by priests have piled up across Europe, including in the pope's native Germany. Benedict's own actions as an archbishop in Munich and later as a cardinal at the helm of the Vatican morals office have come under question.

Victims of clerical abuse have demanded that Benedict take more personal responsibility for clerical abuse, charging that the Vatican orchestrated a culture of cover-up and secrecy that allowed priests to rape and molest children unchecked for decades.

The Vatican maintains that Benedict, who just turned 83, has cracked down on sex abuse both as pontiff and in his tenure as a top Vatican cardinal.

In his meeting with the Maltese men who said they were abused by priests, a tearful Benedict promised the church will do everything possible to protect children and bring abusive priests to justice, according to the Vatican.