A headmistress has said she is "appalled" that somebody would sink as low as to throw a firework at a group of girls from her school.

Paramedics reportedly had to attend to two injured girls after a firework exploded by their legs.

The shocking incident happened outside Chislehurst School for Girls on Thursday (September 26) at a bus stop.

Karen Raven, headmistress of the secondary school, told News Shopper this morning: "I am appalled that someone would be so irresponsible as to throw a firework at a group of school children.

"My senior staff were on hand and acted swiftly to support our students.

"Parents have been very appreciative of our professional and caring response."

A furious post on a Facebook group, Orpington Gossip, reported the incident before it was shared hundreds of times.

It read: "Today someone (words just fail me to describe an imbecile who would come up with such an idea) has thrown a firework at group of girls outside Chistlehurst School for Girls- at the bus stop, two girls were injured and paramedics had to attend, thankfully the explosive fired at their legs causing 'only" multiple wounds.

"Id like to URGE anyone who was near the scene at the time and seen make/colour of car, or perpetrators faces to come forward. It could have happened to anyone's child, this is sick and I really hope they get caught and punished for attacking children aged 12!"

News Shopper has contacted both the police and the London Ambulance Service for more information.