VATICAN CITY:

Pope Francis, celebrating his first Christmas as the leader of the Catholic church, has called on atheists to unite with believers of all religions and work for "a homemade peace" that can spread across the world.

Speaking to about 70,000 people from the balcony of St Peter's Basilica in his Christmas Day address, the same spot where he emerged to the world as pope when he was elected in March, Francis also made another appeal for the environment to be saved from "human greed and rapacity".

He said people of other religions were also praying for peace, and - departing from his prepared text - urged atheists to join forces with believers.