Beyonce's father has confirmed the singer has given birth to twins.

Reports first emerged in the early hours of Sunday morning that the 35-year-old and her husband Jay Z have welcomed the new arrivals.

Taking to Twitter new grandfather Mathew Knowles confirmed the news, writing: "Happy Birthday to the twins! Love, Granddad."

Posting a photo of balloons he added: "They're here!#beyonce #twins #jayz #happybirthday."

Reporting the news a source told People magazine the music couple are over the moon with their baby news. "Bey and Jay are thrilled and have started sharing the news with their family and closest friends."

On Saturday an unidentified female was pictured delivering a pink and blue balloon and floral gift with one reading: 'It's a boy' and the other reading: 'It's a girl.' The accompanying envelope had: 'To B & J' on the front.

According to TMZ the twins will remain in hospital as doctors deal with a minor issue.

Sources close to the couple said: "The twins were born Monday in a Los Angeles hospital. We're told a "minor issue" surfaced, and as a result ... doctors do not feel comfortable releasing them."

Although the nature of the issue has not been clarified, an insider added that Beyonce remains at the hospital but 'is okay. The babies are expected to be okay as well.'

In February the Formation singer broke the internet with her pregnancy announcement after posting a photograph of her sizeable baby bump on social media.

Confirming that she was expecting twins Beyonce wrote: "We would like to share our love and happiness. We have been blessed two times over. We are incredibly grateful that our family will be growing by two, and we thank you for your well wishes. - The Carters."

The Halo singer's mother Tina Knowles shared her excitement as she anticipated the arrival of her new grandchildren. "I'm so excited. I can't wait," she said.

According to Mail Online Tina, 63, also praised Beyonce who has a five year-old daughter Blue Ivy, for being an 'incredible parent.'

She said: "[Beyoncé and Jay Z are] incredible parents. She's a really good mom. Really patient and kind. [My biggest lesson was] teaching them that what is on the inside counts more than what's on the outside. I see her passing it on, and it makes me really proud because that was my biggest lesson."