Vatican City, Nov 10 (Reuters): Pope Francis on Wednesday (Thursday NZ time) chastised priests and bishops who take pictures with their cell phones during masses, saying they should focus on God instead.

"The priest says 'lift up your hearts'. He does not say, 'lift up your cell phones to take pictures,'" Francis told tens of thousands of people at his weekly audience in St Peter's Square, referring to a communion prayer in the Roman Catholic Mass.

In his improvised remarks, he called using cell phones during Mass "a very ugly thing," adding: "It makes me very sad when I celebrate (Mass) here in the piazza or in the basilica and I see so many cell phones held up. Not only by the faithful, but also by some priests and even bishops!

"The Mass is not a show ... so remember, no cell phones!" he said, prompting laughter and applause from the crowd.

Francis, the leader of the world's 1.2 billion Roman Catholics, has regularly urged the faithful to be more spiritual and his priests and bishops to be more humble.

Shortly after his election in 2013, he said it pained him to see priests driving flashy cars and eager to use the latest smartphone.

The pope is driven around in a simple blue Ford Focus and is not known to have ever used a cell phone in public since his election.