DANVERS, Mass. (AP) – A Wal-Mart in Danvers re-opened Sunday as fire officials continued searching for the source of noxious fumes that evacuated the store Saturday and sent about 60 people to hospitals.

Customers and employees said a gas-like odor was causing shortness of breath, nausea and burning eyes.

Police responded to a 911 call at about 2:30 p.m. Saturday.

Danvers Fire Capt. Frank Sacco said it will be difficult to pinpoint the source of the gas because the episode was relatively short.

Some victims reported Sunday that they still had sore throats, but most had recovered, Sacco said. The store re-opened Sunday at 9 a.m.

Authorities ruled out carbon monoxide and said the air conditioning and ventilation system in the store was in good working order.