Harry Styles battled through illness at One Direction's concert in Pennsylvania on Monday (08Jul13) and refused to bow out after reportedly vomiting onstage.

The 19-year-old appeared visibly unwell while performing at Pittsburgh's Consol Energy Center, and worried fans watched as the singer suddenly set his microphone down and bolted behind a stage prop, while his concerned bandmates tried to cover his solos.

In footage of the incident, captured by a fan at the side of the stage, Styles can be seen crouching over as though he is being sick, and he then grabs a towel to wipe his face and takes a swig of water.

But the show went on for the pop star - he later re-emerged to finish up the gig with the rest of the group.

Neither Styles nor his bandmates have addressed the onstage incident.