has asked people to pray for him as the head of the Catholic Church continues to receive oxygen.

Vatican sources have said the pontiff, 88, is eating normally and tests continue to be carried out at Rome's Gemelli hospital where doctors have been treating Francis for double pneumonia.

Francis said in a message from his hospital bed, quoted by Sky News: "I am confidently continuing my hospitalisation at the Gemelli Hospital, carrying on with the necessary treatment; and rest is also part of the therapy!

"I sincerely thank the doctors and health workers of this hospital for the attention they are showing me and the dedication with which they carry out their service among the sick."

He added: "In recent days I have received many messages of affection, and I have been particularly struck by the letters and drawings from children.

"Thank you for this closeness, and for the prayers of comfort I have received from all over the world! I entrust you all to the intercession of Mary, and I ask you to pray for me."

Sources at the Vatican have said the message was written over the last few days.

In an update earlier on Sunday, the Vatican said the pope had "rested well" overnight. A text prepared by Francis was read at Sunday's Angelus service at the Vatican in his absence.

FOLLOW BELOW FOR UPDATES...