Hong Kong police seized high-powered explosives during a raid on a suspected bomb-making factory on Friday night, on the eve of planned protests across the region over the weekend.
A 27-year-old man was also arrested by the police from the "homemade laboratory" in Tsue Wan, according to CNN.
Two kilograms (4.4 pounds) of high explosives, 10 petrol bombs, corrosive liquids, weapons and metal poles have been seized by the police in Friday night's raid.
"It's the largest such seizure we have ever come across in Hong Kong," Alick Mcwhirter, the superintendent of the Explosive Ordinance Disposal (EOD) Bureau, said.
Flyers linked to the anti-extradition bill protests were also found on-site during the raids, CNN added.
Both pro-government and anti-extradition bill protests are scheduled for Saturday and Sunday across Hong Kong.
While the police were still testing the seized materials, they believe that triacetone triperoxide (TATP) was found at the site of the raid.
Law enforcement officials have already carried out a controlled explosion and are slated to carry out more throughout Saturday.
TATP is the same explosive which was used in the November 2015 Paris attacks, the March 2016 Brussels bombings and the 2017 May Manchester bombing, according to CNN.
Pro-democracy demonstrations have been taking place regularly across Hong Kong for the last six weeks. They were initially triggered by an extradition bill which would allow China to extradite suspects from Hong Kong to face trial in the mainland.
Even though the bill has been suspended, protests urging for government reforms amongst other things continue.
( With inputs from ANI )