Oaxaca, Mexico - Mexico's ombudsman opened an investigation this weekend after an indigenous woman gave birth in the garden of a public clinic, sparking a social media storm.

A witness's picture, published on social media and newspapers, shows 28-year-old Irma Lopez, kneeling and crying with the boy on the lawn still attached to the umbilical cord outside the health center in the southern state of Oaxaca.

The incident caused outrage, with Mexicans taking to Twitter to denounce it as new examples of the poor quality of health care in impoverished parts of the country and the discrimination indigenous groups face.

The office of Raul Plascencia, head of the National Human Rights Commission, said in a statement that an investigation was opened into the alleged abuse of the ethnic mazateca woman who gave birth in a garden "because she was denied medical attention."

The Oaxaca state human rights office also launched a probe over the October 2nd incident at the health center in San Felipe Jalapa de Diaz, a town of 6,000 people.

"We have repeatedly detected anomalies in the health sector in Oaxaca, and mainly offenses against indigenous women or women who live in marginalized areas of the state," Oaxaca State Human Rights Commission president Arturo Pemibert said.

The director of the health center, Adrian Cruz, told reporters the incident took place "due to the lack of medical personnel, because the doctor on morning duty arrives at 8:00 am and the woman arrived at the clinic at 7:30."

Cruz said the woman asked to be examined but since the doctor had not arrived, the nurse told her to wait.

"But she was embarrassed that they saw that she was feeling discomfort and she left the waiting room. I think that labor began at that moment, which is why she gave birth outside the clinic," Cruz said.

San Felipe Jalapa de Diaz Mayor Silvia Flores said it was the second such case this year after another woman gave birth to a girl in the clinic's garden in July "because there was no personnel on duty."

In both cases, the babies were declared in good health.

The majority of Mexico's 14 million indigenous peoples — out of a national population of 118 million — live in Oaxaca.