A fire on board a New Jersey-bound United Airlines plane prompted it to return to San Diego International Airport on Tuesday morning and four people were taken to a hospital for treatment for smoke inhalation, authorities said.

Flight 2664 was heading to Newark Liberty International Airport in New Jersey when a passenger�s external battery pack caught fire shortly after takeoff, authorities said.

Passenger Caroline Lipinski told KFMB-TV that a few minutes after takeoff, a bag belonging to a first-class passenger began smoking.

�He threw something on the ground and it was a battery charger pack or something from his laptop, it burst into fire,� she said.

�There was smoke in the cabin, I was terrified,� she said.

Passenger Stephan Jones said some passengers �were gasping, screaming� while flight attendants grabbed fire extinguishers and ran to the front of the plane.

The crew placed the battery in a special fire bag, which prevented it from spreading, and the Boeing 737 returned safely to the airport at around 7:30 a.m., authorities said.

Four passengers were treated for smoke inhalation at a hospital, UC San Diego Health said in a statement.

Several flight attendants were taken to the hospital as a precaution, United Airlines said in a statement that thanked crew members �for their quick actions in prioritizing the safety of everyone on board.�

Two other people declined to be taken to the hospital, the San Diego Fire-Rescue Department said.

The remaining passengers departed for New Jersey aboard a second plane at about 11:45 a.m., KSWB-TV reported.

The Federal Aviation Administration will investigate the incident.

Lithium-ion batteries are widely used in electronic devices but also have been known to overheat and cause fires. Airlines permit them on carry-on luggage but not in checked bags.

In December, a Lufthansa flight from Los Angeles to Germany was diverted to Chicago after a laptop caught fire on board.

Also in December, A JetBlue plane from Barbados to New York was evacuated in New York after a fire that may have started with a battery, authorities said. More than 160 passengers were evacuated using emergency slides. Five received minor injuries.

A fire sparked by a lithium-ion e-bike battery injured more than three dozen people in New York last November.

(AP)