Ms Sinnott was the mother of an 11-month-old baby girl when she disappeared from her home village of Broadway in 1998.

The PSNI said groups of young people are gathering in the Broadway area of south Belfast.

Police said some of the young people were behaving ‘recklessly, dangerously and in some instances criminally around Broadway roundabout’.

Police were attacked with petrol bombs, paint and bottles by a crowd of around 40 young people in the Broadway area.

'It’s an invitation to be part of something truly special," says Boyle Arts Festival