Pope, on Palm Sunday, pays tribute to 'today's martyrs'

Pope Francis leaves the main altar as he leads the Palm Sunday mass at Saint Peter's Square at the Vatican March 29, 2015. REUTERS/Giampiero Sposito

VATICAN CITY (Reuters) - Pope Francis led the world's Roman Catholics in Palm Sunday celebrations by paying tribute to those killed for their faith, a reference to the victims of Islamic State militants.

Francis, who earlier this month began the third year of his papacy, presided at a colourful procession in St. Peter's Square commemorating the day the Bible says people of Jerusalem welcomed Jesus days before he was crucified.