SYDNEY, Australia (AP) -- On a day when there was another rush of Olympic travelers, noxious fumes that appeared to come from a cleaning solvent escaped into part of Sydney's international airport.

 Dozens of people were treated for stinging eyes and difficulty breathing Wednesday in a section of the airport that was quickly sealed off.

 Ambulance, police and fire crews were called to the departure terminal in response to reports of a "major gas leak," said Andrew Hall, a spokesman for the New South Wales state Ambulance Service.

 Authorities said 27 people were taken to a hospital and 40 more treated at the scene, authorities said.

 "Most have been treated with oxygen and saline in their eyes to ease the irritation," said Caroline Hancock, an ambulance spokeswoman.

 An initial investigation indicated the fumes were caused by a cleaning solvent that spilled into the airport's air conditioning system, said ambulance spokesman Ian Krimmer.

 "It was a routine substance used in routine cleaning of air conditioning," he said. "There has been a minor spillage causing a vapor which has caused discomfort to some people."

 The fumes did not disrupt any flights or airport services, and no Olympic passengers were affected, said Sydney airport spokesman Peter Gibbs.

 "Olympic passengers in the inbound passenger area were completely unaffected," Gibbs said.

 However, the immigration area and surrounding duty-free shops on the outbound side of Australian customs were closed for about two hours.

 Sydney airport is handling the heaviest workload in its history as tourists, athletes and Olympic officials stream in for the games, which begin Friday.

 Greg Russell, director of aviation for Sydney Airport Corp., said the airport's air conditioning system had been shut down and fans were turned on to clear the air.

 When the fumes were first noticed, an announcement in the terminal told passengers to stay in the departure lounge until further notice.

 That restriction was lifted soon after, and passengers were diverted around the affected area to their flights.