LONDON >> Several athletes competing at the world championships have come down with a stomach bug, the event’s organizing committee said Monday.

All of them have been staying at the same official hotel.

“There have been a number of cases of gastroenteritis reported by team members residing within one of the official team hotels for the world championships,” the organizing committee said in a statement. “Those affected have been supported by both team and LOC medical staff, in addition we have been working with Public Health England to ensure the situation is managed and contained.”

It was not immediately clear how many athletes were affected, but Botswanan runner Isaac Makwala said he was among the ill.

Makwala, who has already qualified for the 400-meter final, pulled out of his opening heat in the 200 on Monday. He wrote on his Facebook page that he was not the only one affected.

“According to IAAF medics I am apparently suffering from food poisoning which has affected several other athletes,” Makwala wrote. “Let’s hope they will allow me to run my final.”

Makwala was expected to be the main challenger to Wayde van Niekerek in both the 200 and the 400.