Police scanned students for weapons at a secondary school this morning but did not find any.

Officers set up knife arches at Harris Academy Merton this morning as part of a routine operation which takes place two or three times a year.

Students are not warned about the scanning in advance, headteacher Leo Gilbert said.

Wimbledon Times:

Officers in action at Harris Academy Merton. Picture @MPSMerton

He said: "It is not because there has been an incident, it is something we do periodically.

"It is to work with the local police and send a clear message to students and staff that our priority is to keep them safe."

The school in Wide Way, Mitcham, saw bags being searched and people being scanned as they went through the school gates.

Mr Gilbert added that in the six or seven years since they had run the operation, they have never found any knives or other weapons.

Because it is unannounced, he said there were people on hand to look out for students attempting to evade the arches.

Police confirmed it was a routine check and not in response to any particular incident.