Little Mix have become stronger than ever over the past four years.

The four-piece British band – made up of Perrie Edwards, Jesy Nelson, Leigh-Anne Pinnock and Jade Thirlwall – marked the anniversary of their rise to fame on Wednesday.

And to honour the special occasion, the girls revealed their love for each other via Instagram in a touching post.

“#4YearsOfLittleMix wow what an incredible day we have had.. 4 girls, 4 years and each year we get a little stronger (sic),” the group wrote. “We cannot tell you how important our friendship/sisterhood is to us, we have been through so much together and generally love each other more than anything. May Little Mix last forever, coz we'll tell you something, we dno what we would do without each other.

“Thank you to our beautiful mixers for sharing this special day with us, without you we wouldn't even be here! You are the reason we do what we do! Love always! Your girls.”

Despite the happy nature of the occasion, the day turned out to be somewhat emotional for band member Perrie.

The 22-year-old singer has had a difficult few weeks after her former One Direction star fiancé Zayn Malik dumped her, reportedly via text message.

Despite looking strong at various public events since the split, Perrie struggled to control her emotions as she and Little Mix performed their track The End in New York on Wednesday.

The girls were belting out the emotional song as part of a fan event, which was streamed live globally, when Perrie broke down in tears as she sang the lyric: “No one can love you, the way I used to do.”

Jade, Leigh-Anne and Jesy were quick to comfort their bandmate, with Jesy telling the crowd: “It’s been a long day.”