Jennifer Aniston's birthday celebrations hit a serious snag when her private jet was forced to make an emergency landing on its way to Mexico.

The actress and several friends were on their way to Cabo San Lucas, Mexico when the plane was forced to circle back and land at Ontario International Airport in Ontario, California, a source confirmed to People. The airport was closed down so the plane could land without much fanfare, allowing Anniston and her friend to await a new plane.

An early tweet from Ontario International Airport regarding the incident revealed that both police and fire fighters were "on alert" for an incoming plane. No further information was available at the time.

"ALERT: ONT and the City of Ontario Police and Fire Departments are currently on alert for an incoming aircraft. More information to follow," the message read.

A second tweet read, "FINAL UPDATE: Incoming aircraft, Gulfstream – N729TY, landed safely at ONT. OPD and OFD are on the scene."

The airport addressed the incident in a later statement, revealing that 10 people had been on the plane. The group was able to land "without incident" following a mechanical problem with their initial aircraft.

"A Gulfstream aircraft with 10 passengers and two flight crew members on board landed without incident at Ontario International Airport (ONT) after experiencing landing gear difficulty," the statement said. "The plane was en route Friday from Los Angeles International Airport to Cabo San Lucas when it was discovered that one of the four rear tires had displaced. The aircraft landed safely at ONT around 2 p.m. Friday."

The news comes about a week after Aniston celebrated her birthday with friends like Courtney Cox, Gwyneth Paltrow, Ellen DeGeneres, and ex-husband Brad Pitt. The event "was a celebration of Jen's life," according to an insider.

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