HONG KONG (AP) — The death toll of Hong Kong’s high-rise apartment blaze rose to 159 on Wednesday, as authorities arrested six people on suspicion of deactivating some fire alarms during maintenance work at the housing complex.

The youngest person who died in the fire was a 1-year-old infant, police said. The oldest was 97.

Police said they have completed a search for bodies inside all seven of eight high-rise residential towers ravaged in the fire that first broke out last Wednesday and took until Friday to be extinguished. About 30 people were still reported missing.

“We have not finished our work yet,” Commissioner of Police Joe Chow told reporters, adding that officials found suspected human bones in different apartments and will attempt DNA testing on the remains to identify them.

Officials will also continue to search through piles of fallen bamboo scaffolding to check if any remains or bodies were buried there, he said.

The deadly blaze broke out at Wang Fuk Court, in the northern suburban district of Tai Po, which was undergoing a monthslong renovation project with buildings covered by bamboo scaffolding and green netting.

Police and the city's anti-corruption body said Tuesday that they had arrested 15 people as authorities probe corruption and negligence in relation to the renovation work. Substandard plastic nylon netting covering scaffoldings erected outside the towers and foam boards installed on windows were found to have aided the fire's rapid spread, authorities said earlier this week.

Chris Tang, Hong Kong's Secretary for Security, said police are investigating the Binzhou Inspection and Testing Center in China, which provided the safety inspection certificate for the construction netting.

Meanwhile, officials said the city will remove all external scaffolding nets from ongoing renovations. The materials will need to be tested before they are allowed to be installed again.

In addition to the scaffolding issue, residents and officials have said that some fire alarms in the buildings failed to sound when the fire broke out, though it was not clear how widespread that problem was within the complex.

Police said Wednesday that six people who allegedly deactivated some fire alarms at the housing complex during the renovation works were arrested on suspicion of making false representation to the fire services department.

The initial cause of the fire was still under investigation.

Nineteen bodies among the 159 were still unidentified, police said. Ten migrants who worked as domestic helpers at the housing complex, including nine from Indonesia and one from the Philippines, as well as one firefighter, were among those killed in the fire.