SAN PEDRO GARZA GARCIA, Mexico (AP) — At least nine people, including a child, were killed and 121 injured when a stage collapsed during a campaign rally in northern Mexico amid strong winds, the governor of Nuevo Leon state said Thursday.

The collapse occurred during an event on Wednesday night attended by hopeless presidential candidate Jorge Álvarez Máynez, who was forced to flee. Videos of the collapse on social media showed people screaming, running away and climbing out from under metal posts.

The victims “will not be alone in this tragedy,” Máynez told reporters on Wednesday evening, adding that he had canceled upcoming campaign events.

Afterwards, soldiers, police and other officials roamed the grounds of the park where the event had taken place, while many sat nearby, stunned and shaken by the tragedy.

In a video message, Nuevo Leon Governor Samuel Garcia, a leading member of Maynez's Citizens' Movement party, said 94 of the injured had been treated and discharged, but 27 were still in hospital. State health authorities said many of the injured had skull fractures. Garcia said several victims were undergoing surgery and some appeared to be in critical condition.

Garcia said the accident happened “within seconds.”

Mexican President Andrés Manuel López Obrador said most of the injured were women and exonerated Máynez's Citizens' Movement party – widely seen as a tacit ally of López Obrador's Morena party – before investigating the allegations.

“We know that they are not to blame,” the president said on Thursday. Condolences poured in from all over Mexico, including from the other two presidential candidates.

Máynez wrote on his social media accounts that he went to a hospital in the affluent suburb of San Pedro Garza Garcia, near the city of Monterrey, after the accident. He said he was in good condition.

“The only important thing now is to take care of the victims of the disaster,” he wrote.

Videos of the accident showed Máynez waving his arm as the crowd chanted his name. But then he looked up and saw a huge screen and metal structure falling towards him. He quickly ran to the back of the stage to avoid the falling structure, which appeared to be made up of relatively light frame pieces, as well as what appeared to be a screen with the party's logo and theatrical lighting.

In a Facebook post, Alejandra Gamez Escalera wrote that her father and 11-year-old stepbrother were killed in the collapse. She said they had gone to the event to listen to a band that was scheduled to play at the campaign rally.

“If you had just stayed home and not gone to the event, none of this would have happened,” Gamez Escalera wrote.

Máynez is third in the presidential polls, behind frontrunner Claudia Sheinbaum of the ruling Morena party and opposition coalition candidate Xóchitl Gálvez. Both sent their condolences, and Sheinbaum canceled a campaign rally the next day in nearby Monterrey “out of solidarity” with the victims and their families.

“My condolences and prayers go out to the families of the dead and I wish a speedy recovery to all those injured,” Gálvez wrote in a social media post.

The accident occurred at the height of the campaign season, which saw many events this week and next in the run-up to the presidential, state and local elections on June 2.

The election campaign had so far been marred by the murder of around two dozen candidates for local office.