DHAKA: Two leading popes of the 20th Century, John Paul II and John XXIII, are to be declared saints at an unprecedented open-air ceremony in Rome on Sunday.

A Mass co-celebrated by Pope Francis and his predecessor Benedict will be witnessed by one million pilgrims and a vast TV and radio audience.

Nearly 100 foreign delegations are due, including royal dignitaries and heads of state and government.

It is the first time two popes have been canonised at the same time, reports the BBC.

Correspondents say the move is being seen as an attempt to unite conservative and reformist camps within the Roman Catholic Church.

Pilgrims have been pouring into Rome and special bus, train and boat services ferried many more into the city early on Sunday morning for the two-hour ceremony which starts at 10:00 local (0800 GMT).

Some had bagged places to sleep overnight as close as possible to St Peter’s Square, hoping to be among the first in when it opens to the public.

Giant screens have also been erected in nearby streets and elsewhere in the city for those unable to get into the square.

BDST: 1235 HRS, APR 27, 2014