More than 200 Traveller caravans have taken up residence along the roadside and in the main car-park in Knock to attend the August 15th celebrations.
Yesterday was the second day of the annual national novena at the shrine and Traveller families from around the country attended in large numbers.
Earlier this week, about 10 caravans managed, despite barriers at the entrance, to enter the main car-park in Knock and set up residence. Throughout Thursday, families with caravans and other vehicles parked along the main road of the village. Gardaí said yesterday the large numbers of Travellers' vehicles parked on the roads into Knock were causing some traffic disruption.
It is believed that most of the families will move out today.
Up to 100,000 pilgrims are expected to attend ceremonies at Knock over the nine-day novena.
At the height of the pilgrimage season, an alert on the local water supply has been in force since Thursday. Mayo County Council said a general coliform bacterial contamination was discovered and all water for consumption should be boiled before use.