The Latest on the Vatican's conference on dealing with sex abuse by priests (all times local):

9:20 a.m.

Pope Francis has warned bishops and religious superiors summoned to a landmark sex abuse prevention summit that the Catholic faithful around the world are demanding more than just condemnation of the crimes but concrete action to put an end to the scandal.

Francis opened the summit Thursday by praying for help turning "this evil into a chance for understanding and purification."

He told the gathering of 190 leaders of bishops' conferences and religious orders that they bore the responsibility to "listen to the cry of the young who want justice."

Francis called the summit after botching a well-known sex abuse cover-up case in Chile last year. Realizing he had erred, he has vowed to chart a new course and is bringing the rest of the church leadership along with him.

9 a.m.

Pope Francis has opened a high-level summit of church leaders on preventing clergy sex abuse, hoping to impress on bishops from around the world that the problem is global and requires a global response.

The four-day meeting at the Vatican began early Thursday with prayers and was to feature speeches, tutorials and workshops on protecting children, preventing abuse and stopping cover-ups.

More than 30 years after the scandal first erupted in Ireland and Australia and 20 years after it hit the U.S., bishops and other Catholic superiors in many parts of Europe, Latin America, Africa and Asia either deny that clergy sex abuse exists or downplay the problem.

Francis has made the same mistakes. He finally did an about-face after botching a well-known sex abuse cover-up case in Chile last year.

7:30 a.m.

Activists in Poland have pulled down a statue of a disgraced late priest after increasing allegations that he sexually abused minors.

They acted under cover of night early Thursday to protest the failure of the Polish Catholic Church to deal with the problem of sex abuse by priests.

Video footage shows three men attaching a rope around the statue of the late Monsignor Henryk Jankowski in the northern city of Gdansk and then pulling it down. Jankowski was a prominent priest in the Solidarity pro-democracy movement in the 1980s who died in 2010.

The private broadcaster TVN24 reported the three were arrested.

Their action comes as Pope Francis gathers church leaders from around the world at the Vatican to grapple with the sex abuse crisis in the church.