Feng Renjie, an assistant professor at Peking University, was fired after a woman who claimed to be his girlfriend accused him of having sexual relationships with at least nine women, the university confirmed on Thursday.

The university announced on its Weibo account it applies "zero tolerance" to violations of teacher ethics and will deal with the case in accordance with university regulations.

The announcement came after a woman who claimed to be Feng's girlfriend posted on a WeChat account on Dec 3 that Feng Renjie, an assistant professor at the university's school of mathematical sciences, seduced several women, some of whom are students, to sleep with him or marry him.

The woman said in the post she found in Feng's WeChat messages that from March to August, he had sexual relationships with at least nine women and told them that he wanted to marry and have children with them.

In August on Chinese Valentine's Day he dated three girls separately, including the whistleblower.

She also found out one of his ex-wives was his student. They got married in 2016, when the student was only a sophomore, and got divorced last August. The student, surnamed Tang, was in a relationship with another student when Feng approached her.

He usually chatted with these girls in an honest way and told them he was not good at dating girls but really wanted to get married.

Meanwhile, he registered on a matchmaking website and also let his friends introduce him to blind dates.

The woman posted screenshots of alleged conversations.

After Feng realized his affairs were discovered, he allegedly threatened to kill the woman then himself.

The university has revoked Feng's teacher qualifications.