(Reuters) - The father of pop star Beyonce turned to Twitter on Sunday to say his daughter was now the mother of twins, confirming earlier reports of the year's most highly anticipated celebrity birth.
"They're here!" wrote Mathew Knowles in a tweet that included a digital birthday card that read: "Happy Birthday to the twins! Love, Grandad."
The message was the first word from a family member about the birth of the twins, which took place last Monday, according to several entertainment media websites that quoted unnamed sources. Reuters has been unable to confirm the reports.
Neither Beyonce, one of the world's most popular singers, nor her husband, the rap star and entrepreneur Jay Z, has made any announcement about the birth.
Social media was abuzz in February when the 35-year-old singer, whose full name is Beyoncé Giselle Knowles-Carter, posted a photo of herself wearing a long veil and lingerie and caressing a noticeable baby bump.
In 2012, the birth of the couple's first child, Blue Ivy, caused a media sensation, leading New York's Lenox Hill Hospital to shut down part of its maternity wing to accommodate music's royal couple.
TMZ said its sources reported that Beyonce gave birth to a boy and a girl on Monday and all three remained in a Los Angeles hospital because of a "minor issue."
All three will be "okay," the entertainment website reported on Sunday.
Beyonce, who has sold more than 100 million records as a solo artist, was formerly with Destiny's Child, a group managed by Mathew Knowles.
Thanks to a successful world tour and the hit album "Lemonade," she was the second highest-paid entertainer in the year ended June 1, earning $105 million, Forbes said. Only Sean "Diddy" Combs, at $130 million, topped her.
(Reporting by Bernie Woodall in Fort Lauderdale, Fla.; Editing by Diane Craft and Peter Cooney)