Pope Francis has washed the feet of 12 inmates, including three women and a man who is converting from Islam to Catholicism.

Although in Jesus's time, washing the feet of one's guests was performed by slaves, Jesus "reverses" this role, the Pope said during the Holy Thursday Mass of the Lord's Supper at a prison 45 miles from Rome.

"He came into this world to serve, to serve us. He came to make himself a slave for us, to give his life for us and to love us to the end," he said.

Pope Francis made his way by car to a prison in Paliano, which houses 70 men and women who testified as a witness for the state against associates or accomplices.