Pope Francis has celebrated Palm Sunday mass in St Peter’s Square a day after leaving hospital where he was treated for severe bronchitis.

Francis, 86, arrived in the square, in which more than 30,000 people had gathered, onboard the popemobile.

The vehicle stopped by the ancient obelisk in the centre of the square for the pontiff’s blessing of the palms before transporting him to the altar.

He opened the mass with 'a weak and slightly breathless voice', Italian media reported

Pope Francis celebrates Palm Sunday mass day after leaving hospital