(Getty Images)

Could Justin Bieber have a broken heart?

After news broke last weekend that the Biebs had split with his girlfriend of almost two years, Selena Gomez, the "Boyfriend" singer played an emotional, acoustic version of Justin Timberlake's "Cry Me a River" during his Boston concert Saturday. Timberlake wrote the 2002 hit about his own break-up with Britney Spears.

"Thank u Boston. focused on the positive. #30MillionBeliebers with me. Im never leaving u because u r always there 4 me. love u. Night," Bieber tweeted after the concert.

When asked about his relationship earlier that day, Bieber, 18, didn't give any details.

"I don't know what to say," Bieber, 18, told Open House Party radio host John Garabedian. "I don't know what's going on in my life . . . To even assess that it doesn't make sense 'cause I have not made any comment."

As for Gomez, the 20-year-old kept herself busy at a K-Mart in White Plains, N.Y., Saturday where she promoted her Dream Out Loud clothing line.

A source close to Justin Bieber and Selena Gomez confirmed to ABC News Radio Saturday that the pair had gone their separate ways.