MEXICO CITY: At least 57 students at a rural secondary school in the Mexican state of Chiapas were poisoned by an unknown substance, according to local officials.

The third mass poisoning in Chiapas schools reported in local media over the past two weeks, which alarmed parents and worried students, occurred on Friday.

Also Read: Mexico's mayor was killed in a massacre at a town hall

The Mexican Social Security Institute reported Friday that 57 teenage students from the rural Bochile community had presented at a neighborhood hospital with symptoms of poisoning.

According to the institute, the condition of all the students is stable, except one who was taken to a hospital in the state capital in a "critical" condition.

Officials did not speculate on the cause, but local media reported that some parents think the students may have consumed contaminated food or water.

In a statement, Bochil's leaders said "we are outraged by these incidents," and added that they are assisting a state prosecutor's investigation.

Social media videos showed a frenzied scene in which adults carrying teenagers dressed in school uniforms ran out of hospital halls screaming anxiously.

Also Read:  Story of the Haunted Islands of Dolls in Mexico

After hearing rumors on local media and on social media that the students had tested positive for cocaine, the state prosecutor's office posted on social media on Saturday that it had taken 15 toxicology tests, all of which came back negative.

In a Facebook video posted on Saturday, several parents gathered at the secondary school's basketball court and demanded information from officers, as more than a dozen police, some wearing shields, stood and watched.

One of the men in the video claimed that his daughter had been poisoned and that he and other students had tested positive for cocaine in a private laboratory.

Also Read:  Brazil holds a historic election in which Jair Bolsonaro faces off against Luiz Inacio Lula da Silva

Asked earlier about the poisoning incidents, the state prosecutor's office said it would continue to test the students.
Since September 23, Tapachula town has reported two cases of widespread poisoning, affecting several students.