Spice Girls star Melanie Brown has said she hopes the sound "will be much better" for their next gig after some fans complained about the sound during their first show.

The pop group took to the stage for the first time in seven years at Dublin's Croke Park on Friday night to kick off their highly-anticipated stadium reunion tour.

More than 70,000 fans turned out to see Brown, Geri Horner, Emma Bunton and Melanie Chisholm perform the 1990s group's biggest hits in the dazzling show, which included a number of outfit changes and messages of diversity and unity throughout.

Fans at the concert praised the group for their show, which opened with a performance of Spice Up Your Life and a fireworks display.

However, some took to Twitter to complain about being unable to hear the group during the show, which saw many pay more than £100 for a ticket, commenting on the poor quality of sound in the stadium.

Melanie Brown of the Spice Girls in concert at Croke Park in Dublin

Brown - otherwise known as Mel B - thanked their fans for attending the Dublin show in a video message on her Instagram story.

She added: "We will see you in Cardiff. And hopefully the vocals and the sound will be much, much better, pfft."

Geri Horner of the Spice Girls in concert at Croke Park in Dublin
Melanie Brown of the Spice Girls in concert at Croke Park in Dublin

Another wrote: "Anyone else think the sound is crap at the @spicegirls ? £spicegirls £spicegirlsdublin."

"The sound at the Spice Girls at Croke Park is awful," another said while one wrote: "@spicegirls at the show in Croke Park and can't hear a word from your mics, turn it up."

Melanie Brown, Geri Horner, Emma Bunton and Melanie Chisholm of the Spice Girls in concert at Croke Park in Dublin

Another added: "There’s something wrong when the crowd at spice girls concert are all sitting down because no one has a clue what song is on because the sound really is THAT bad..."

A third wrote: "You've gone to all the effort of taking the time off work, travelling, booking accommodation and paid through the nose for a ticket. Not good enough."

Spice Girls fans (left to right) Liz Devine, Rebecca Byrne and Laura Reddy arrive at Croke Park stadium in Dublin for The Spice Girls World Tour

However, the concert was largely well-received from those who attended, with one fan tweeting: "Such a surreal night last night at the Spice Girls. Reliving the childhood was amazing, felt so emotional.

"Best night ever #SpiceWorldTour2019 #GirlPower #wannadoitagain."

Another wrote: "@spicegirls what can I say yous didn't disappoint!! Amazing from start to finish. All our dreams came true. #SpiceWorld2019 have lost my voice because I screamed like a 15year old girl. Memories forever #friendshipneverends."

Geri and Mel C at Croke Park

The show kicked off with Baby, Scary, Ginger and Sporty taking to the stage in extravagant fashion for their first number, wearing hand-embellished Swarovski crystal costumes designed by Gabriella Slade.

Geri Horner donned a floor-length sparkling Union flag gown, Emma Bunton wore a shimmering pink mini-dress, Brown had a glittering animal print jumpsuit for the occasion while Melanie Chisholm sparkled in a shining Olympian outfit.

They opened the show with the message: "We welcome all ages, all races, all gender identities, all countries of origin, all sexual orientations, all religions and beliefs, all abilities."

Geri at the Croke Park show

Horner greeted the crowd saying: "Welcome to Spice World. Spice girls, spice boys, everyone is welcome. We want every single one of you to feel special tonight. Like a king or a queen, we celebrate you. But I got to say there are a lot of queens here tonight."

Chisholm told the crowd it was very special for the band to be back in Dublin.

The Spice Girls in Dublin

She said: "In '98, we started our world tour in Dublin, so we truly are home. It's got a very special place in our hearts."

During the show, they performed a number of their hits including Who Do You Think You Are?, Viva Forever, Wannabe, 2 Become 1, Say You'll Be There, Mama and Stop.

Geri Horner of the Spice Girls in concert at Croke Park in Dublin

The stage, which featured an imposing Spice World sculpture and large screens on each side, was used to display messages of female empowerment, including "We are stronger together" and their motto "Girl Power".

It is the first time the group has performed since the closing ceremony of the London Olympics in 2012.

The group are undertaking the 13-date tour without original Spice Girls member Victoria Beckham, who has decided not to join them.

Fans wear Spice Girls T Shirts as they arrive at Croke Park stadium in Dublin
Spice Girls fans (left to right) Julie Anne Murphy, Emma Lynch and Maxine Allen, as they arrive at Croke Park stadium

The band had to deny rumours of a rift in April following Brown's claims that she had a one-night stand with Horner in the Spice Girls' heyday.

But on the opening night, there did not appear to be any tension between the girls, who all laughed and joked with each other throughout the show.

The Spice Girls will head to Cardiff's Principality Stadium (May 27), the Etihad Stadium in Manchester (May 29 to June 1), Coventry's Ricoh Arena (June 3-4), Sunderland's Stadium Of Light (June 6), Edinburgh's BT Murrayfield Stadium (June 8), Bristol's Ashton Gate Stadium (June 10) and London's Wembley Stadium (June 13-15).