Metro Manila (CNN Philippines) — A Saudia Airlines flight was placed in an isolation area at the Ninoy Aquino International Airport (NAIA) on Tuesday.

The Manila International Airport Authority (MIAA) said its Emergency Services Department had received an advisory from the NAIA control tower that Saudia Airlines Flight SV872 was "under threat."

Passport check

Speaking to CNN Philippines Chief Correspondent Pia Hontiveros, Saudia SV872 passenger Engr. Dimasira Macabando said their flight had landed at 2 p.m., but that the passengers were being kept inside the aircraft.

Macabando said the pilot told them that the police would board the plane to inspect their passports. He said everything seemed "very normal" in the flight, but that they got news reports from outside that their plane had been hijacked.

While speaking to Hontiveros, Macabando said passengers at the front of the plane were allowed to disembark and that they were waiting to leave the plane, as well.

The passengers were able to disembark at around 5 p.m. and were held at the immigration area for an hour. At around 7:30 p.m., most of the passengers started leaving the airport.

'False alarm'

Saudia Airlines, meanwhile, said on its official Twitter account that the situation with Flight SV872 was a "false alarm."

MIAA General Manager Eddie Monreal said in a press briefing that the distress call was a "pilot mistake" by one of the four Saudi Arabian pilots. Upon verification by airport tower officials, a pilot sent a verbal confirmation that they indeed pressed the "distress button."

This led airport authorities to implement security measures. However, while taxiing the aircraft to the gate, the Saudia pilots said they just accidentally pressed the button.

Monreal said the MIAA and the Civil Aviation Authority of the Philippines or CAAP will independently investigate the pilot for pressing the emergency button twice.

CNN Philippines Correspondents Makoi Popioco and Rex Remitio and Digital Producer VJ Bacungan contributed to this report.