US Education Secretary Betsy DeVos has been prevented from entering a public school in Washington D.C. by a group of protesters.

DeVos, who was a controversial pick from Donald Trump, was physically blocked from entering Jefferson Middle School, with several parents holding banners standing in her way as she attempted to enter.

Forced away from the school, DeVos got into a vehicle and drove away, and it is not yet clear if she later returned to the school.

Washington D.C. Mayor Muriel Bowser later tweeted about the protest, which was organised by the Washington Teachers Union, saying: "This bears repeating: Protest - peaceful protest - is fine but we do not condone violence towards anyone.

"DC has the fastest growing urban school district in America. We welcome @BetsyDeVos & anyone who wants to learn more about our schools."

The union, who were not among those who blocked DeVos from entering the school, said they were there to send a message about their support for education for all and the public school system, WJLA reported. The union also said they hoped DeVos would succeed in her role in order for public schools to succeed.

DeVos faced criticism from several teachers' unions before her appointment was even confirmed, with her pro-voucher and charter school views coming under fire from those who claim she has no experience or interest in the public school system.

The vote on her appointment came down to a 50:50 deadlock, with Vice President Mike Pence casting the deciding vote in her favour and not a singe Democrat voting for DeVos' appointment.