Passengers Sick On Boeing Plane
Seven passengers had to be hospitalized after complaining about a strong odor on a United Airlines flight. Here, a plane takes off from San Francisco International Airport on Aug. 24, 2012 in San Francisco. Justin Sullivan/Getty Images

A strong odor led to a United Airlines flight making a diversion on Friday.

The flight, whose origin was Baltimore-Washington Airport, was en route to San Francisco when it made an emergency landing at Washington Dulles International Airport. While it landed without a mishap, it was met by the Fire and Rescue Department. Seven passengers had to be taken to a local hospital for evaluation, according to a statement.

"Before take-off, you could detect a faint smell of fuel which I thought nothing of," passenger Raman Santra told CNN. "As we continued to go to cruising altitude, the smell became very strong." The scent caused passengers to complain of chest pain and nausea.

United Airlines later told passengers that the aircraft required "prolonged ventilation system maintenance," Santra said.

In a statement to Fox, the carrier said, “The aircraft landed safely and taxied to a gate. Customers were immediately deplaned and evaluated by medical personnel. Several customers were transported to local hospitals."