Five teenagers have been arrested in connection with the blaze that closed the M1 in both directions for six days.
The boys, aged between 14 and 17, were arrested in a series of morning raids across Barnet and Harrow in north London yesterday. They are being held in connection with the fire that damaged an elevated section directly above a scrapyard on 15 April and two other fires in nearby Mill Hill.
A seven-mile stretch of the motorway was closed near Scratchwood Services in north London between junctions one and four. Further closures may be needed for permanent repair work to be carried out.