A United Express plane made an emergency landing in Arizona after an onboard threat was made against the plane Thursday afternoon, MyFoxPhoenix.com reported.

The United Express 5573 flight from San Francisco to San Antonio landed at Sky Harbor Airport in Phoenix around 4:45 p.m., MyFoxPhoenix.com reports. The 43 passengers, two pilots and two flight attendants were taken off the plane.

Phoenix police spokesman Sgt. Steve Martos said the threat was made on the plane, though he said he couldn't provide further details. A bomb squad boarded the plane and searched for anything suspicious.

He said that a bomb squad and police dogs searched the plane and luggage "to make absolutely sure there's no threat," and nothing dangerous was found. Martos said that all of the passengers were interviewed and cleared to continue their journey.

By 7:15 p.m., Sky Harbor spokeswoman Deborah Ostreicher said the passengers were being rescreened to resume their trip to San Antonio on Thursday night.

"No further information is available about the specific security issue that caused the flight to be diverted to Phoenix, but the passengers are all safe and police are investigating," Ostreicher said.

In comments late Thursday night, Martos also declined to elaborate on the specific nature of the security issue.

The plane that was searched was isolated on the northwest side of airport and Sky Harbor officials said the incident wasn't causing any flight delays.

United Express is the brand name for several regional airlines that operate shorter flights for United Airlines.

The Associated Press contributed to this report.

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