Residents were baffled by a half-blue half-white sky.

Footage shows the atmosphere divided into two blocks with different colours in Bukidnon province, the Philippines, on March 31.

Local Jovelyn Lascona, who saw the phenomenon from the grass field near her home, said: ‘The sky suddenly turned half blue and white. We thought the heavens was trying to tell us something.'

Despite sparking worries among the residents, the bizarre sight was caused by an atmospheric optical phenomena called crepuscular and anti-crepuscular rays. They happen during twilight hours, when the sun is below the horizon.

Crepuscular rays appear to radiate outward from the sun's position below the horizon, causing the white sky. On the other hand, anti-crepuscular rays appear to converge towards the point in the sky opposite to the sun's position causing the blue sky.