At 15 today, a number of students at the Balder Gymnasium in Skellefteå became sick. On social media, students describe how they became ill.

"Whose did you put in the food?", One student writes.

- We do not know that it is food poisoning. What we do know is that 15 people have registered sick. We need to investigate what this is, says Peter Lundmark, meal manager at Skellefteå municipality.

"No one felt bad before lunch"

One of those who became ill was Johanna Karlsson, who goes first year on a natural science line at the school.

- We have a class chat and there many wrote that they felt bad and wanted to vomit, some had to run toa pretty much. Everyone in the class felt bad except for one.

Johanna Karlsson feels pretty confident that the food was over the top.

"Nobody felt bad before lunch," she says, adding that the food at the school is usually good.

"Always turns on the big drum"

Over a thousand people ate tacos at Balderskolan today and in case of suspicion of food poisoning, samples of the food will be sent for analysis. Peter Lundmark thinks that more people should have gotten sick if it is the food that is the culprit.

- But we always turn on the big drum when there are suspicions and have routines for this.

Pupils who have stomach ailments are urged to contact customer service and the municipality tries to get hold of students who have become ill.