A warehouse blaze in Harbin City in northeast China's Heilongjiang Province that killed 5 firefighters still hasn't been completely extinguished, local firefighters said on Sunday.

Heavy machinery clear the debris of a burnt warehouse at the Beifangnanxun ceramics market in Daowai District, Harbin, capital of northeast China's Heilongjiang Province, Jan. 4, 2014.[Photo/Xinhua]

As of 10:40 a.m. Sunday, a residential building next to the warehouse was still smoldering. Rescuers said that the source of the fire has been hard to determine due to the building's complicated structure, and the building is at risk of collapsing. Firefighters are still working to extinguish the flames.

Experts have suggested dismantling the residential building.

A fire broke out at a warehouse at the Beifangnanxun ceramics market in Daowai District at 1:14 p.m. on Friday.

The firemen were buried by debris while trying to put out the fire, which burned down the third floor of a market warehouse at 9:37 p.m. on Friday, burying firemen on the second floor.

A total of five firefighters were killed and another 14 were injured in the blaze.

The open flames were put out at about 11 a.m. on Saturday.

The warehouse is part of an 11-story residential building. The first to third floors are used as a warehouse for household supplies, including brooms and plastic products. The remaining eight floors are residential.

The fire has continued to burn for more than 30 hours.