About 30,000 flag-waving worshippers joined an open-air mass held by Pope Francis in mainly Muslim Bahrain on Saturday, the highlight of his outreach mission to the Gulf.

Some of the congregation had tears in their eyes as they waited to see the 85-year-old at Bahrain National Stadium, the kingdom's biggest venue.

Francis, who uses a wheelchair and walking stick due to knee problems, smiled and waved to the crowds from an open-sided popemobile where he was seated, flanked by more than a dozen suited security guards and attendants.

As a 100-strong, multinational choir sang in multiple languages, the Argentine stood to kiss children lifted up to greet him in the popemobile which drove slowly towards a white stage backdropped by a giant yellow cross.

The pope is on his second visit to the resource-rich Gulf -- the cradle of Islam -- after his 2019 trip to the United Arab Emirates, where he held a mass for 170,000.

"We've been here since one o'clock. We didn't sleep," said volunteer Philomina Abranches, 46, an Indian-born Bahrain resident.

"We are so excited. We all call him 'Papa'. More than anything, he represents peace in the world. This is what we need now."

Margerite Heida, 63, also a Bahrain resident, said: "Hosting Pope Francis is the best feeling. This is the greatest event of the year."

Heida was waiting for her second look at the pontiff.

"I saw him yesterday in the church", she said. "I consider myself lucky to be able to see him. I was also able to hold his hand yesterday and got his blessings."

Many worshippers came to catch a glimpse of the pope from around the Gulf region, which has about two million Catholics, mainly foreign workers from South Asia and the Philippines.

Everyone at the stadium received a plastic bag containing a white baseball hat, a paper Vatican flag, a bottle of water, a booklet with details of the mass and some biscuits.

Pope Francis's 39th international visit is largely aimed at building ties with Muslim officials. On Friday he met the grand imam of Egypt's Al-Azhar mosque, one of the leading authorities of Sunni Islam, and members of the Muslim Council of Elders.

He also attended a service at Our Lady of Arabia Cathedral, the biggest in the Arabian peninsula that seats more than 2,000. Hundreds of migrant workers were among the congregation welcoming him.

Later on Saturday, Francis will meet children at the Sacred Heart School.

On Sunday, he is to attend a prayer meeting at the 83-year-old Sacred Heart Church -- the oldest in the region -- before flying back to Rome.