Niall Horan celebrated his 21st birthday last night (06.09.14).

The One Direction hunk - who doesn't officially turn 21 until September 13 - threw an early party at Shoreditch House in London to mark the milestone with his celebrity pals, before he flies back to the US to continue with his band's 'Where We Are' world tour.

Taking to his Twitter account today (07.09.14), he tweeted: ''What a great night last night! Thanks everyone for coming to celebrate my 21st with me! Had a great night with friends and family (sic).''

Louis Tomlinson, 22, appeared to be the only member of One Direction to attend the bash, but he didn't arrive solo as he was joined by his girlfriend Eleanor Calder.

Presenter Laura Whitmore, 29, was also in attendance and kept fans updated with the party antics by posting pictures from the night on her Instagram account.

At the beginning of the evening she posted a snap of party guests sitting at a table wearing Niall masks, which she accompanied with the caption: ''So apparently someone is turning 21... (sic).''

Niall's parents and his brother Greg flew from Ireland to the English capital for the celebration, and his older sibling took to his Twitter account to mark the occasion with a heartfelt message for the singer.

He tweeted: ''Big love bro nearly 21 wow I remember the day u were born mate love you more than anything and I'm so proud x x (sic).''

Other party guests included soccer star Frank Lampard and his girlfriend Christine Bleakley, Jamie and Louise Redknapp, singer Brian McFadden and James Corden.

Meanwhile, One Direction will resume their tour at the Pasadena Rose Bowl in California on September 12.