Pope Benedict has celebrated a mass in Erfurt, Germany, and met with former German Chancellor Helmut Kohl in Freiburg, during a four-day state visit to his homeland.

Some 30,000 people were estimated to have attended Saturday's mass in Erfurt, shortly after security forces arrested a man who allegedly fired an air rifle near the crowd. Papal officials said the incident had nothing to do with the pope. No one was injured.

Later Saturday, the pope flew to Freiburg in southern Germany, where he met with the former chancellor. Pope Benedict's visit has been focused on unity among Christians, while Mr. Kohl is considered one of the driving forces behind the reunification of East and West Germany in the late 1980s and early 1990s.

The pope is on his first state visit to Germany. His arrival Thursday drew thousands of protesters at the Berlin airport. Protesters were carrying banners about sexism, homophobia and anti-Semitism.

On Friday, the pope held a meeting with a very small group of Catholics who say they were sexually abused by members of the Catholic clergy. The Vatican said afterward that the pontiff expressed his “deep compassion and regret” to those victims. But critics said the meeting did nothing to solve the problem.

Also Friday, the pope met with Muslim leaders in Berlin, where he called for Christianity and Islam to grow together in “dialogue and mutual esteem.”