Hong Kong police said on Monday night that they had defused two "complete, fully functional" nail bombs discovered in the grounds of a school by a janitor.

Containing a total of 10 kilograms of powerful explosives and nails, and designed to be set off using a mobile phone, the bombs were "ready to be used" and had only one function, "to kill and to maim people", senior bomb disposal officer Alick McWhirter told reporters.

With the police still conducting an investigation, it is too early to point a finger at the anti-government forces as being responsible for the bombs.

Yet, as the unrest that has plagued the city enters its seventh month, the bombs should sound the alarm that there are some in the city who have relinquished their conscience and who, for whatever purpose, are willing to use the unrest as an opportunity to create a bloody spectacle.

After more than half a year's fruitless struggle, the signs suggest that there are some in the opposition camp who are intent on "stirring all in the pan" by resorting to an act of violence that targets both civilians and law enforcers. These are not the first bombs found by the police, and the weapons the police have seized so far are likely only the tip of an iceberg.

The police recently raided two radical organizations on the anti-government side — namely "Dragon Butchers" and "V Squad" — seizing large numbers of lethal weapons after learning their members planned giving Hong Kong the seasonal gift of a "gory Christmas Day".

All Hong Kong residents should be aware that some conscienceless individuals intent on fishing in the troubled waters have already made up their minds to step back from the crowds so they can put both police officers and civilians — including children — in their crosshairs.

Undoubtedly, Hong Kong has come to a crucial crossroad, and deciding which path to take should not be in question for any in Hong Kong not reveling in violence for violence's sake. That includes those somnolent young disrupters, who canceled their campaign to paralyze the city's traffic on Monday morning because it was too cold — 16 C to be exact.

For such creature-comfort-loving would-be "revolutionaries", the unrest is clearly a game, which they participate in as the mood takes them. They should be aware that some are willing to take the game a lot more seriously and are raising the stakes they are willing to play for. Terrorist acts are as indiscriminate as their fundamental purpose is, not just to kill, but shock. Those thinking they will be somehow spared because they are on the "same side" could find themselves in for a rude awakening.