BBC News Online examines how such sweeps are organised.

The link has often been made between truancy and street crime - and in the London Borough of Hackney, education welfare officers and the local police team up for truancy patrols.

Officers do not wear uniform on these days, so as not to appear obtrusive and also to prevent children from running away as soon as they approach.

There would not normally be more than two or three police and welfare officers on patrol together.

In some urban areas, truancy sweeps may focus on shopping centres, but in Hackney, the centre of attention is usually the streets.

"The sweeps tend to be around the estates where they live," a spokeswoman for Hackney Council said.

"Hackney doesn't have a major shopping centre, so it tends to be around the streets - maybe in the vicinity of the school."

Age of child

It is the age of the child that gives education welfare and police officers their cue to intervene.

If they see a child of school age wandering the streets, they will approach him or her - whether or not the child is with an adult - and ask why they are not in school.

If, for example, the youngster claims to be going to the dentist, the truancy sweep officers may ask to see an appointment card.

But if the absence is clearly unwarranted or unauthorised, the police then have the power to return the child to their school.

The matter is then followed up by the education welfare officer who will speak to the child's parents and keep an eye on the child's school attendance record.

Parental responsibility

A series of truancy sweeps in Hackney in the month of May led to 35 children being identified as truants - 10 of these were with their parents.

It is the education welfare officer's job to challenge parents and stress their responsibility.

"It has to be pointed out to them that they have a legal duty to make sure their child is in schools," the Hackney council spokeswoman said.

"They can't just say 'We're going to get some new shoes'."

Again, the education welfare officer follows up the case, possibly with a home visit.

And learning mentors in schools may also be asked to help encourage a truanting child to turn up to lessons.