CHICAGO (AP) – A United flight from Boston landed safely at O’Hare International Airport after reports of smoke in the cockpit, while another flight was delayed for more than two hours Sunday when flight attendants became concerned about passengers’ behavior.

No one was hospitalized in either incident, but one person reported a sprained ankle after exiting United Airlines Flight 525 from Boston by an inflated chute, said Wendy Abrams, a spokeswoman for the city’s aviation department.

Flight 525 was close to landing in Chicago when the pilot noticed smoke in the cockpit and declared an emergency, said United spokeswoman Megan McCarthy.

The plane carrying 58 passengers and six crew landed safely at O’Hare around 7:20 a.m.

A fire was not reported on board the Airbus A320 and the cause of the smoke was being investigated, McCarthy said. “They’re taking a very close look at the plane and really going to look at everything,” she said.

The second plane, United Airlines Flight 1498 from Ft. Lauderdale, Fla., was delayed at O’Hare when a flight attendant noticed “security concerns” before takeoff, McCarthy said.

The attendant notified the pilot that some of the plane’s 111 passengers were not in the correct seats, a passenger had entered the bathroom and another was using a cell phone, said Officer Marcel Bright, a spokesman for the Chicago Police Department.

“All these things were going on, and at this point the pilot decided to return to the gate based upon these observations made by the flight crew,” Bright said. “No unnecessary chances are going to be taken. When a pilot or airline believes there is a problem we will check it out.”

Chicago police swept the plane with a canine unit after it returned to the terminal, but officers did not find any problems and allowed all passengers to reboard the plane after being rescreened, Bright said. No one was arrested.

“No one got in any serious trouble, except their flight was delayed,” Bright said.

The plane left O’Hare around 9:30 a.m., more than two hours after its scheduled 6:50 a.m. departure, McCarthy said.