A headteacher has defended enforcing her school's uniform policy by sending home "teenage girls who flash large amounts of thigh".

Parents have complained on social media after Alison Colwell turned away pupils who failed to obey the uniform policy at Ebbsfleet Academy in Kent, which includes a rule banning skirts that sit more than 5cm above the knee.

Ms Colwell said about 20 pupils were sent home on the first day of term on Tuesday.

She said: "We have a clear uniform policy that we enforce. Our rules are no stricter than most schools, it's just that we are consistent in enforcing them.

"Parents were warned about this last term and students who chose to break the rule yesterday were given the choice to borrow a school second-hand skirt.

"The tiny minority of parents who choose to defy us, and our rules, are a minority - it's a curious parent who thinks it is acceptable for teenage girls to flash large amounts of thigh, or worse.

"The overwhelming majority of our parents are fantastic and support what we are doing and the tremendous achievements of the academy since opening three years ago."

Ms Colwell said, following an Ofsted inspection last term, the school was rated good and was praised for "strong leadership" which "has led to higher academic standards, better behaviour and increased attendance".

One parent wrote on Facebook that her 15-year-old daughter had been turned away for wearing a skirt that she had worn previously to the school. She said "about 200 other girls" had been refused entry.

She said: "They're letting their pupils down by turning them away, they're shutting the gates in their faces for silly reasons.

"I'm very angry - school is a place where these kids should be able to feel safe, they just want to go to school."

Ms Colwell has received criticism from some parents over her policy of enforcing school uniform rules since she took over at the school in 2012.