Two cousins aged 14 and 15 have been reported missing from their home in Newton Aycliffe.
Thomas and Kieran Miller have not been seen since Sunday.
The police say they are concerned because of the age of the boys.
More top news
Seven men have been summonsed to court to answer charges in relation to allegations of abuse by young men at Medomsley Detention Centre.
The singer's solo tour kicks off in Edinburgh in April and will see him play venues across the UK and Ireland.
The prisons watchdog has flagged up high levels of violence and severe drug problems at a large men's training jail.