A second United flight departing New Jersey's Newark Liberty International Airport in the last two days has had to make an emergency landing.

The Federal Aviation Administration says United Flight 409 bound for Seattle returned to the airport at about 9:15 a.m. Sunday after reports of possible smoke in the cabin and cockpit.

A United spokesman says the flight crew noticed an unusual smell in the cockpit. No injuries were reported.

The emergency was the second in as many days. On Saturday night, a United flight to Germany had to return to the airport after experiencing engine problems.

On Sunday, the FAA said one of the engines on the Berlin-bound flight apparently overheated on takeoff. An agency spokeswoman says that contrary to published reports, the aircraft didn't blow a tire during takeoff.