Here's a cool photo:

A Singapore Airlines plane was seen in the sky over Changi accompanied by two Republic of Singapore Air Force F-16 fighter jets.

The photo was taken on March 26 morning, when flight SQ423 from Mumbai had to be escorted safely back to Changi Airport after a bomb threat was made mid-flight at about 11.35pm local time -- but turned out to be a hoax.

The photographer, who was at Changi Business Park at that time, took the photo after 7.40am by chance.

He said he was waiting for the lift at the ninth floor when he saw the planes approaching from East Coast.

F-16s scrambled

Major Jireh Ang, 32, a fighter pilot from the 143 Squadron, said that two fighter jets were scrambled within minutes of being notified of the threat at 7.04am.

This caused an audible sonic boom for the people on the ground.

Ang said: "It was only when we were airborne that we received details and further orders of the mission. Our regular and rigorous training has ensured that we are always ready for the task when called upon."

The RSAF works with other national agencies to monitor the Singapore skies and respond swiftly and decisively to any potential air threats on a 24/7 daily basis, he said.

Planes flew close enough

Even though the photo showed the three planes flying at a distance away from one another, they got close enough earlier on to achieve visuals of one another.

The Straits Times reported that the fighter jet pilots established communications with the SIA plane pilots through the assigned radio frequency after successfully intercepting the commercial aircraft.

"We informed that they were being escorted by the RSAF fighters and for them to comply with all instructions," Ang said.

"We also got the pilots' visual attention, and at the same time, we were able to observe if there were any abnormal activities within the cockpit and the cabin."

What happened

No suspicious item was found when the plane was checked through after landing.

A woman and a child were held back for questioning.

The Boeing 777-300ER aircraft had 263 passengers on board. More than 20 people missed their connecting flights.

RSAF has written about the incident: