Hong Kong police arrested five men and four women on Monday for allegedly manufacturing explosives on the eve of this week’s poll on political reform.
Although police spokesman Ng Wai-hon couldn’t establish a link between the suspects and the polls, she said one of the suspects is a member of a "radical group."
"During police inquiries someone claimed to be a member of a local radical organisation," Au said.
The explosive materials were found in an abandoned television station in the eastern district of Sai Kung.
Police then found three bottles of “major raw material” which is used to make triacetone triperoxide (TATP) explosives in a house.
"The operation... resulted in the arrest of nine Hong Kong citizens for the offence of conspiracy to manufacture explosives," Au Chin-chau, superintendent of the organised crime and triad bureau, told reporters.
Maps of the Chai and Admiralty districts where last year’s mass pro-democracy rallies took place as well as a government complex in Admiralty were also seized.
The South China Morning Post and the Oriental Daily claims that suspected bomb makers are from pro-democracy “localist” groups which organised the protests against the government's electoral roadmap.
An unnamed police officer claimed that the activists were members of a Hong Kong separatist organisation which has already made plans on the web to detonate a bomb days ahead of voting, according to the South China Morning Post.
It is expected that there will be many protests in Hong Kong against a controversial political reform package which is causing political debate in the country.
Police also warned people not to take part in any demonstrations due to the seized maps, which shows the Hong Kong’s roads street by street.
"Should there be any confrontations, citizens should protect their own safety, leave the scene at once and maintain a safe distance with the violent protesters," Au said.
The reform bill lays out a plan giving the right to the public to choose the next leader for the first time in 2017.
After the declaration of the bill, Hong Kong was divided into two parts since last fall’s pro-democracy “Umbrella Revolution.” Pro-democracy activists have demanded full democracy and almost total autonomy from the Beijing.
But according to the plan, candidates must be chosen by a loyalist committee which is set up by Beijing. The activists have refused the regulation, calling it a “fake democracy.”