A flat in Tuen Mun appeared to have been struck multiple times by lightning on Thursday morning.

A dramatic video shared on social media by Tuen Mun resident Carol Tam, which went viral on the internet, showed the same flat at Wo Tin Estate being hit three times within seconds.

A former assistant director of the Observatory, Leung Wing-mo, called the incident rare but normal, saying lightning conductors do have their limitations.

"The lightning conductor acts as a safety umbrella," he said. "So there is always a limit to the area that it can protect."

But Leung, who’s also the spokesman for the Meteorological Society, said people need not be too worried even if their buildings are hit by lightning.

"The structure of any building nowadays is a case where it offers additional protection, because we have a lot of concrete, iron, steel bars and so on."

"Only when someone is very near the window or touch the metal part of the window... then in that case there could be a possibility of being hurt by the electricity”.

The Observatory said more than 10,000 lightning strikes were recorded when the thunderstorm and amber rainstorm warnings were in force in the morning.