ZHENGZHOU, July 1 -- The death toll from a fire in an apartment building in central China's Henan Province last week has risen to 15, as local authorities confirmed two more deaths on Wednesday.

The blaze engulfed the ground floor of the building in Zhengzhou, Henan's capital, at around 2 a.m. on June 25. Nine bodies were found at the scene, and eight people were hospitalized, with four of them dying within a few hours.

Zhengzhou fire authorities said that two more have since died, bringing the death toll to 15. The remaining two are in a stable condition.

According to firefighters, clutter piled in a corridor caught on fire and emitted toxic smoke. Most of those killed were hotel employees who lived on the seventh floor. Upon seeing the building was on fire, they panicked and ran downstairs, where they were suffocated by the toxic smoke.

The cause of the accident is under investigation.