On Saturday morning a man fired three air gun shots in Erfurt, Germany, around one mile (1,6 kilometers) from the city’s main cathedral (Saint Mary), where Pope Benedict XVI was to celebrate Mass.

The shooting incident has occurred on the edge of the security zone about an hour before the Pope started his celebration of the Mass for around 30,000 people. The gun fires aimed at a security guard.

Eckhard Deutschmann, a local police spokesman told AFP that no one was injured in the incident and a suspect was arrested in his apartment, from where the shots were fired.

Pope Benedict XVI celebrates a Mass Saturday morning at Saint Mary's Cathedral in Erfurt, Germany, about an hour after the shooting incident.(AP)

When the man was arrested, the Pope was already at the airport on his way to the staunchly Catholic city of Freiburg, the final stop on this visit, where he holds a prayer vigil for young people later on Saturday.

“According to the German police, it seems to be the action of an unbalanced person,” said Federico Lombardi, Vatican spokeman. It was “an incident that had nothing to do with the Pope” and “the Pope has not been informed,” he said.

There was “no worry” in the papal entourage over the incident, and the pontiff was not informed about it before the Mass. “It didn’t seem particularly urgent,” he told reporters on the pope’s plane after the Mass.

There has been very tight security for the Pope’s first state visit to his native Germany. Large parts of Berlin, Erfurt and Freiburg have been locked down for the trip and large police forces were deployed.

On the Mass celebrated early Saturday, Pope Benedict XVI paid tribute to those Catholics who had kept the faith burning during Nazi and Communist regimes in Erfurt, former East Germany. The most resilient Catholic community under the Communist regime was in Erfurt.

Pope Benedict XVI prays during the Mass held in Erfurt after the shooting incident.(AP)

“You have had to endure first a brown and then a red dictatorship, which acted on the Christian faith like acid rain,” Pope Benedict XVI said. “Are not the deep roots of faith and Christian life to be sought in something very different from social freedom? It was actually amid the hardships of pressure from without that many committed Catholics remained faithful to Christ and to the church,” Pope said.

Germany’s Church has been losing thousands of followers because of revelations that hundreds of children and young people were abused by clergy and church employees, the scandal has cost them badly needed trust among the roughly 24 million German Catholics.

The victims groups and their lawyers has been accused Pope Benedict XVI of being part of a systematic cover-up by the church hierarchy for pedophile priests in his earlier roles as an archbishop in Germany and later at the pontiff.

On Friday night, Pope Benedict XVI met for half an hour with two women and three men from parishes across Germany who were among the abused. He expressed “deep compassion and regret” at the suffering of those who were abused and assured them the Church is seeking “effective measures to protect children,” Vatican said.

Survivors groups denounced the pope’s meeting with German victims as an empty gesture. They maintain the church has not done enough to prosecute offending priests and prevent future cases of abuse.

Catholic leaders had warned ahead of Pope Benedict XVI visit that there was no quick solution, but they hoped the pontiff could help heal wounds left by the scandal.

Germany’s Bishops Conference has set up a telephone hotline to counsel victims and help them to take legal steps against offending priests when possible.

About 9,000 people turned out in Berlin to denounce the Vatican views on homosexuality, contraception and other issues.

On the first two days of his visit, the Pope met members of Germany’s Jewish and Muslim communities and then held prayers with Protestant leaders in a show of greater Christian unity.