CAIRO — Military helicopters flew overhead and police fanned out in force Saturday as Pope Francis celebrated an open-air Mass for Egypt’s tiny Catholic community on the second and final day of a visit aimed at comforting Christians following a series of attacks by Islamic militants.

Despite the security concerns, Francis zoomed around the Cairo sports stadium in an open-topped golf cart before the start of Mass, evidence of his desire to be close to his flock at all costs.

The crowd cheered him wildly, waiving Egyptian and Holy See flags and swaying to hymns sung by church choirs. The defense ministry’s stadium has a capacity of 25,000, but it was less than half-full, a reflection that Catholics represent less than 1 percent of Egypt’s 92 million people.

In his homily, Francis urged them to be good and merciful to their fellow Egyptians, saying “the only fanaticism believers can have is that of charity!”

“Any other fanaticism does not come from God and is not pleasing to him!” he said.

It was a very pastoral message after Francis on his first day demanded that Muslim leaders renounce religious fanaticism that leads to violence.

Francis made the appeal during a landmark visit to Cairo’s Al-Azhar, the revered, 1,000-year-old seat of Sunni Islam learning that trains clerics and scholars from around the world.

Security was exceptionally tight around the stadium and in the upscale neighborhood where Francis spent the night, with uniformed and plain-clothed police stationed every yard or so along his motorcade route.

But Francis decided to forego the bulletproof “popemobile” that his predecessors used on foreign trips and drove through Cairo in a simple Fiat, his window rolled down.

His gestures sent a defiant message to the extremist Islamic State group, whose local affiliate in Egypt has vowed to go after Egypt’s Christians to punish them for their support of President Abdel-Fattah el-Sissi.