China's government has ordered a halt to work by a medical team that claimed to have helped make the world's first gene-edited babies.

Vice Minister of Science and Technology Xu Nanping told state broadcaster CCTV Thursday that his ministry is strongly opposed to the efforts that reportedly produced twin girls born earlier this month. Xu called the team's actions illegal and unacceptable and said an investigation had been ordered.

Researcher He Jiankui claims to have altered the DNA of the twins to try to make them resistant to infection with the AIDS virus. Mainstream scientists have condemned the experiment, and universities and government groups are investigating.

There is no independent confirmation of what He says he did. He has said a second pregnancy may be underway.