Bloc Party drummer Matt Tong is being treated in a US hospital for a collapsed lung after becoming unwell during a concert in Atlanta.
In 2005 Bloc Party were nominated for a Mercury Music Prize
The 27-year-old was taken ill shortly after coming off stage, and was rushed to hospital where he is due to stay for at least the next three days.
Doctors say he is in a comfortable condition and not in any danger.
The band have cancelled a number of shows, including a sold-out date at New York's Madison Square Garden on Monday.
A spokeswoman for the band said Tong may have sustained the injury while drumming.
"Matt is known for his energetic drumming style," she said. "It's not clear at this stage when he will be fit to resume performing."
The band, who earned a Mercury Music Prize nomination in 2005 for their debut album Silent Alarm, are touring the US with fellow group Panic! At The Disco.