Pope Benedict is blaming Europe's economic woes on economies driven solely by profit.

The pope spoke to reporters on his papal plane shortly before arriving in Madrid Thursday to attend a four-day Catholic youth festival.

He said economies needed to be guided by ethics and serve the common good, instead of being based on “the maximization of profit.”

Benedict's visit to Spain is his third since becoming pope and comes as the country's unemployment rate has soared to 21 percent. The job crunch has hit Spain's youth especially hard, and the pope urged the throng of young people who greeted him at the airport to maintain their faith.

The pope was also greeted by King Juan Carlos and other top officials. Benedict will meet with Spanish Prime Minister Jose Luis Rodriguez Zapatero, whose government has promoted several policies opposed by the church, including relaxing Spain's divorce laws, easing restrictions on abortion, legalizing same-sex marriage and allowing gay couples to adopt children.

Highlights of the World Youth Day celebrations include a mass confession and prayer vigil Saturday in the presence of the pope and a celebration of Mass on Sunday morning.

More than one million young Catholics from around the world are expected to pour into Spain for the papal visit.

The cost of the papal visit has sparked some anger, with bitter debates erupting over the visit's estimated $72 million cost and the Catholic Church's role in Spanish politics.

Riot police in Madrid clashed with demonstrators Wednesday on the eve of the pope's arrival. Thousands marched through the streets, shouting critical slogans.

Police said eight people were arrested and 11 others hurt in the street violence.

Criticism of the four-day papal visit has come mainly from the “Indignant Ones” protest movement, which has been protesting the country's economic woes, government spending cuts and 21 percent unemployment.

On Tuesday, Spanish police arrested a Mexican chemistry student who was allegedly planning to attack those protesting the Pope's visit. Authorities say he was planning to use asphyxiating gases and other chemical substances. The student was freed on bail Thursday but a judge ordered him to surrender his passport and report to a police station twice a day.