Jonathan Knight Leaves Stage During New Kids On the Block Concert

(Rob Kim/Getty Images)

New Kids on the Block hit a bump during one of their first concerts to promote their new album Thursday.

The '90s band, who released their new album "10? this week, rocked the house at New York City's iHeartRadio Theater Thursday night but in the middle of the concert, band member Jonathan Knight left the stage midsong, reported Hollywood Life.

Just before his abrupt exit, Knight reportedly looked uncomfortable and was texting on his phone while the rest of the band danced. Knight then left the stage but returned after two songs, only to leave again after three more.

Knight, who has been open about his struggles with anxiety in the past, tweeted Thursday night, "#ifeelnaked" before adding, "I'm sorry……"

"To recap- Joe was especially dazzling! Jordan was especially amazing! Danny was especially solid & Jon was especially shy! #Allsystemsnormal," band member Donnie Wahlberg tweeted after the show.

"Not 2 worry BHs, all is well w Jon! It was a crazy album release week & we are all on a plane to Napa & look fwd to a grt show this weekend!" the band's official Twitter account tweeted late Friday.

"We love you guys and thank you for your undying support! See you on the road!" they added.

The whole band, including Knight, performed its song "We Own Tonight" on the "Today" show Friday but made no mention of the incident.

The band is set to go on tour this summer with Boyz II Men and 98 Degrees, kicking off May 31 in Uncasville, Conn., and traveling across the country, wrapping July 13 in Minneapolis.

READ MORE: New Kids on the Block, Boyz II Men, 98 Degrees Going on Tour