(TMZ)  - Beyoncé has given birth to a boy and a girl, but an issue surfaced that has kept them in the hospital for nearly a week ... TMZ has confirmed.

Sources connected with the family tell TMZ the twins were born Monday in a Los Angeles hospital. TMZ is reporting that a "minor issue" surfaced, and as a result ... doctors do not feel comfortable releasing them.

TMZ does not know the nature of the issue.

One source told TMZ Beyoncé also remains at the hospital, but as far as we know she's okay. The babies are expected to be okay as well.

It's unclear when everyone will be released.

Story developing ....

Photo: Getty Images