HONG KONG (Kyodo) -- The death toll from Hong Kong's most fatal fire in decades has risen to 146, with some 40 people still unaccounted for, authorities said Sunday, as the semiautonomous Chinese region remains wary about moves seeking accountability turning into protests.

Hong Kong police have arrested a man on suspicion of trying to incite a sedition in relation to the deadly blaze, after he called for setting up an independent investigation committee and holding government officials accountable, according to local media reports.

Some volunteer workers have said the police stopped them from distributing relief supplies such as clothing and food items to evacuees.

On Saturday, Beijing's office for safeguarding national security in Hong Kong accused "anti-China forces" of using disasters to destabilize the former British colony, saying they will be severely punished.

The office alleged those individuals have "spread false information" and "maliciously attacked" the Hong Kong government's rescue efforts to incite social division, seeking to drag the territory "back into chaos of the turmoil and violence in 2019," referring to massive pro-democracy protests that year.

Meanwhile, mourners on Sunday formed a line stretching about 1 kilometer to offer flowers near the burned Wang Fuk Court high-rise housing complex in the northern Tai Po district. Many messages, including "rest in peace," were put on a nearby lamppost.

The blaze enveloped seven of the eight towers in the complex, standing more than 30 stories tall with around 2,000 apartments housing about 4,000 people. It was covered in bamboo scaffolding and green protective mesh for the refurbishment of its exterior walls.