Armed police swooped outside Croydon College last week while the father of Damilola Taylor was inside talking to young people about the dangers of carrying knives.

Richard Taylor was speaking to Croydon students as part of an initiative backed by Manchester United and England footballer, Rio Ferdinand.

But while Mr Taylor made his impassioned plea, police carrying sub-machine guns were outside searching two people.

The dramatic incident was part of a Lambeth police operation. Officers from Croydon's neighbouring force followed a car from Knights Hill in Norwood after a tip-off.

Shocked onlookers saw the specialist officers take the men out of the car before they were asked to stand against a wall outside Suffolk House in College Road.

Mr Taylor was at the college attending a drama performance by the Comedy School, in an event which marked the latest anti-knife crime campaign in Croydon.

He talked to around 200 students before the performance which highlighted the dangers of knife crime.

Mr Taylor said at the event: "I hope the performance reminds you of the dangers of carrying a knife and how this can affect families.

"I want each and every one of you to go about your daily lives and to join me by pledging not to carry a knife or bladed weapon. The police are there to protect us we do not need to take the law into our own hands or carry a knife as protection."

Damilola's father was at the college after launching a national campaign, six years after his son was stabbed in Peckham.

The event was organised by Metropolitan Police schools involvement officers in an attemt to raise awareness of the dangers of carrying knives.

In March Croydon took part in a knife amnesty, as part of Operation Blunt. The amnesty, which used the slogan, "Knives Take Lives" was launched by Anita Brown whose son Gavin died after being stabbed at Parkfields recreation ground in Shirley in October 2005.

Councillor Steve O'Connell, joint deputy leader of Croydon Council said: "Each week lives are horrifically blighted or ended through use of a knife.

"If this show helps people understand the misery that can be caused through carrying a knife - to look big or out of a warped sense of earning respect - then it will be one of the most important and influential performances to be staged in Croydon."

Police said no arrests were made.