A flight leaving Newark Airport turned around shortly after takeoff when it experienced severe turbulence, hurting five flight attendants, officials say.

United Airlines Flight 89, bound for Beijing, returned about 45 minutes after it departed the airport, according to the Port Authority.

Passenger Bryan Munoz, a frequent air traveler, told NBC 4 New York it was the worst turbulence he had ever experienced. Everything started shaking just as the flight attendants had gotten up to start serving passengers, he said.

"It was really fast, sudden," Munoz said. "We lost a little bit of altitude and the plane went side to side. It was a bit nerve-wracking."

While brief -- the turbulence lasted about 30 seconds, according to Munoz -- it was intense enough that the attendants were visibly hurt. One was holding her arm and wrist after the episode, and another was limping, Munoz said.

There were 189 passengers and 16 crew members on board, according to the airline.

After landing, five flight attendants were treated for minor injuries, mainly bumps and bruises. No passengers were injured, officials said.

The passengers were re-booked for another flight Friday morning.

The FAA says it is investigating.