( CNN ) -- Authorities treated more than 700 people for food poisoning after a political rally in southern Mexico this week , officials said . Exactly what caused the food poisoning was unclear , officials from the healthy ministry in Mexico 's Guerrero state said Wednesday . Authorities were testing food and drink samples from the event and sending representatives to communities throughout the area to look for additional cases . Alberta Garcia Adame told CNN affiliate Televisa she started to feel sick after eating egg tacos at a rally Tuesday in Chilapa , Guerrero , for Sergio Dolores Flores , who is running for congress as a candidate for Mexico 's Institutional Revolutionary Party . As the number of cases grew , doctors treated many patients at a local hospital and a temporary shelter at the back of a local church , Televisa reported . Guerrero State Health Secretary Rufino Dominguez said in a statement Wednesday that nearly all of the patients had been treated and released .
Authorities are testing food and drink samples from the event . Health secretary : Nearly all of the more than 700 patients have been treated and released . The hospital is now closed for a week, but will reopen on Monday.