Pope Benedict XVI was knocked to the floor while walking to the altar of St. Peter''s Basilica in Vatican to begin the traditional Christmas Eve service.

The 82-year-old Pontiff fell during commotion that started when an unidentified woman, believed to be mentally unstable, jumped over a barrier. He was back to his feet almost immediately with the help of his bodyguards.

87-year-old French Cardinal Roger Etchegaray, who was near the Pope, was also knocked down. He felt unwell and was taken to hospital for a medical examination.

Despite the incident, the Midnight Mass began as scheduled, at 22:00 local time [21:00 GMT]. This year the service began two hours earlier than usual to ensure that the Pontiff would have enough energy to deliver the traditional Urbi et Orbi speech at noon.