LOS ANGELES (Reuters) - Pop star Justin Bieber and his girlfriend, Selena Gomez, a Disney actress and singer, have broken up, ending a relationship that made them one of Hollywood's most high-profile young couples, media reports said.

Bieber, 18, and Gomez, 20, disclosed their relationship in February 2011 when they appeared together at an Oscar night party after months of rumors of their dating.

E! Online late on Friday was the first to report the split, with other media outlets including US Weekly and People also saying the relationship was over. The reports cited unnamed sources close to the couple.

Representatives for Bieber and Gomez did not returns calls or emails on Saturday.

Bieber has released two No. 1 albums in just over a year - the holiday-themed "Under the Mistletoe" and his latest, "Believe." In September, he topped Billboard's "21 Under 21" list of top young musical acts. It was his second year in a row with the title.

Gomez rose to fame as a teenager in the Walt Disney Co television series "Wizards of Waverly Place" and has enjoyed success as a pop singer.