Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory.

In a demonstration for media cameras, the bomb squad set off a series of controlled explosions in a disused quarry overlooking the city's high-rise skyline, blowing up a watermelon and shredding the front of a minivan.

In July, police announced the seizure of about 2 kilograms (4.4 pounds) of TATP, which has been used in terrorist attacks worldwide. Other recent seizures in Hong Kong involved far smaller amounts, just 1 gram, of TATP, or tri-acetone tri-peroxide.

Members of Hong Kong Bomb Disposal squad gather during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

Members of Hong Kong Bomb Disposal squad gather during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

"Obviously, I’m concerned that they are making TATP or are in possession of TATP,” said Alick McWhirter, the squad's senior bomb disposal officer.

Just 1 gram of the unstable explosive, equivalent to the weight of a candy, could cause life-changing injuries, he said.

A demonstration blast of 1 gram of high explosive at the quarry above the bomb squad's fenced-off headquarters caused a loud bang. A blast involving 50 grams, which would fit into a cigarette packet, sent shrapnel flying from the shattered front of the minivan.

A van sits damaged by the use of explosive by the bomb disposal squad during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

A van sits damaged by the use of explosive by the bomb disposal squad during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

The squad used explosives with a destructive force equivalent to TATP but not TATP itself, because the substance is so dangerous to handle, susceptible to bumps, heat and friction.

“Because I like having 10 fingers, I am not going to use TATP,” McWhirter said.

In October, police said a homemade, remote-controlled bomb intended to “kill or to harm” riot control officers was detonated as they deployed against protests. Causing a loud thud but no injuries, the small blast marked the first known use of an explosive device during the protests that started in June over a contested extradition bill and snowballed into an anti-government, anti-police and anti-China movement.

A van is damaged with TATP explosive by the bomb disposal squad during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

A van is damaged with TATP explosive by the bomb disposal squad during a demonstration for media in Hong Kong, Friday, Dec. 6, 2019. Hong Kong's much-maligned police force provided a rare behind-the-scenes look Friday at its bomb disposal squad to show the potentially deadly destructive force of homemade explosives seized during months of protests that have shaken the Chinese territory. (AP PhotoVincent Thian)

The bomb squad has also disposed of thousands of gasoline bombs prepared by protesters on university campuses.

McWhirter said that “99% of the protesters in Hong Kong, from what I've seen, are peaceful.”

But he added: “There's clearly, though, a small hard core who are dedicated towards violence.”

“The ones creating these explosives are a tiny percentage of a tiny percentage,” he said. “Petrol bombs, TATP, are not the normal in Hong Kong.”

Distrust goes both ways. Protesters accuse police of systematic abuses. The widespread use of police tear gas and thousands of often muscular arrests have infuriated many in Hong Kong. A call for an independent investigation of police conduct features among protesters' key demands.

Later on Friday, protesters planned to rally against the use of police tear gas and to demand information about any health risks from the noxious choking clouds of gas liberally deployed to disperse demonstrators.

McWhirter, a career officer in Hong Kong for 30 years, expressed dismay that relations have soured so dramatically between the police force, long regarded as Asia's finest, and citizens it claims to serve and protect.

“I watched the officers day after day, night after night, month after month, going out and holding the line," he said. “They are being attacked with knives, with explosives and petrol bombs, and they hold the line and use remarkable self-control in the face of incredible violence.”