There's been widespread criticism of US President Donald Trump after he retweeted videos posted by a right-wing group.
He retweeted three clips posted online by the deputy leader of Britain First.
They are unverified, but claim to show Muslims committing crimes.
Downing Street says Mr Trump was "wrong" to share the videos, adding: "Britain First seeks to divide communities through their use of hateful narratives which peddles lies and stokes tensions.
"The British people overwhelmingly reject the prejudice of Britain First that is the antithesis of the values of our country."
Two of the three clips have since been removed from Mr Trump's account.
But one, claiming to show a Muslim migrant beating up a boy on crutches, remians.
In an all capitalised response to the retweets, Britain First said earlier: "Donald Trump himself has retweeted these videos and has around 44 million followers! God bless you Trump! God bless America!"
The group is a far-right nationalist one, known for its anti-Islam and anti-immigration views.