Pope Francis has made a surprise appearance in the Sistine Chapel to welcome a group of 150 homeless people who got a private guided tour, followed by dinner, as part of the pope's ramped-up charity efforts.

Francis told the visitors: "This is everyone's house. It's your house. The doors are always open for everyone."

The Vatican announced earlier this week that the Sistine Chapel would close early to the general public on Thursday to allow the private tour for the homeless. Francis' presence wasn't announced, and he asked that no images of the visit be released by the Vatican.

After blessing the crowd — and asking for their prayers in return — Francis met with each visitor, the Vatican said in a statement.