Small businesses around the Chinachem Tower in Hong Kong’s Central were dealt a blow after the building was engulfed in flames, with some stores remaining shut on Sunday morning as the investigation into the cause of the fire entered its second day.

Some shop operators described the fire as a rarity in the central business district and a source of concern. Saturday’s blaze took more than four hours to snuff out and enveloped the entire building, which was undergoing renovations.

A government spokesman said a day later that a 23-year-old man remained in critical condition at Queen Mary Hospital, while the condition of another man, aged 55, had stabilised following his admission to intensive care.

The investigation into the cause of the fire was ongoing, the spokesman said.

Torres Lee, a shopkeeper at sports shirt store SFALO Kingdom, said Saturday’s fire had unsettled him.

“It was very scary. Police officers came to get us out … at around 4pm they asked us to pull down the shutters and leave soon,” he said.