Paramore has canceled the final two dates on the band’s U.S. tour as frontwoman Hayley Williams continues to deal with a lung infection.

Williams’ condition previously forced Paramore to postpone four shows originally scheduled between July 22 and July 27. The group returned to stage July 29 and has played six shows, the most recent of which took place Wednesday, August 9, in Seattle.

In a Facebook post published Thursday, August 10, Williams writes, “After my lung infection forced us to postpone four shows, I was hoping a week off of performing and a strict medicine routine would allow my body to heal enough to finish off this tour strong.”

“I have been doing everything I can to fight this infection so we wouldn’t have to disappoint anyone with more news of postponements and cancellations,” Williams continues. “After struggling through the last few shows and consulting with my doctor, we’re unfortunately realizing that it’s past the point of wanting to push through to put on a good show for all of you. I’m no risking long term damage and I need to pay attention to my body.”

Williams concludes with an apology to the fans, adding that she “physically can not go on.”

“I know this isn’t great news for anyone,” she says. “Thank you so much for your continued support.”

The affected shows include Thursday in Portland, Oregon, and Sunday, August 13, in Salt Lake City. Tickets will be refunded at point of purchase.

Paramore’s tour, which launched in the U.S. in May, supports the band’s latest album, This Is Why.

The next scheduled Paramore show takes place in October at New York City’s The New Yorker Festival.