My grandson and two female friends walked out of Dulwich park yesterday afternoon, they saw about 15 boys on bikes ahead of them ..... about 10 of these thugs surrounded my g/son and one asked for his phone ..... he refused to give it up to him and the boy threated to "cut him" .... The two girls ran into a doorway of a house ... Thank you to the person that answered the door to them ...... My grandson ran into Dulwich Art Gallery and two very kind ladies helped him ... A huge thank you to them .... We informed the police, my grandson is a Volunteer Police Cadet, and they responded by sending cars to try and find these thugs...... Thank you to the police ...... Just wanted to warn everyone that this is happening.