Two young women have been air-lifted off Croagh Patrick following a fall which left one of them unconscious.
The women were carried off the mountain before being airlifted to Castelbar General Hospital. They were among thousands of worshippers making the annual pilgrimage on Croagh Patrick, a 765-metre peak in Co Mayo.
More than 20,000 people - many of them barefoot, and having fasted last night have attempted the climb.
Before starting the climb they were told that the challenge symbolised the need to regenerate the Catholic Church. The Archbishop of Tuam, the Most Rev Michael Neary, used his homily to urge the pilgrims to look down from the mountain to see the task facing them.
The climb represented the challenge to make the Irish Church more vibrant, he said, adding: "The exciting challenge for all of us is to strengthen, develop and renew our church in a changed and changing Ireland, especially at parish level.
The top section of the climb is notoriously dangerous and with thousands of people on the mountain together there a normally a number of minor injuries.
The summit is the holy ground on which St Patrick, Ireland's patron saint, rested, fasted and reflected during 44 days of lent in 441 AD.