Tunisia's interim health minister says 12 newborn babies have died while receiving care at a public maternity hospital.

Interim minister Sonia Ben Sheikh said during a news conference in Tunis on Monday the infants had been born prematurely and died because of an infection in the hospital.

Ben Sheikh said results from tests to determine how the babies became infected won't be available for at least 10 days. She called the situation "unacceptable."

She says samples from the ' bodies and the hospital have been sent to three different laboratories to ensure the investigation is done in a "transparent and credible way, far from any suspicion."

Ben Sheikh is filling the minister's role following Health Minister Abderraouf Cherif's resignation on Saturday amid a growing scandal over the newborns' deaths. Tunisian authorities have launched multiple investigations.