Fire fighters have basically contained a blaze that has been raging for six hours in a chemical warehouse in the southwest outskirts of Beijing Tuesday.

No casualties have yet been reported.

Zhao Zixin, head of the fire brigade, said they were putting out the last embers of the fire.

A total of 59 fire appliances were in attendance at the site.

He said the fire reported at 6:56 a.m. Tuesday has destroyed an area of more than 5,000 square meters in the warehouse owned by Beijing Yanfang Huaxing Warehouse Logistics Co. Ltd., incinerating stocks of polyethylene and acetone.

A witness surnamed Ren in Xiapo Village, Fangshan District, said she heard an explosion before the fire, which shattered the window in her house.

"I immediately ran out of the house, and saw many villagers looking at the fire and smoke," the woman said.

Dense smoke rose about 1,000 meters into the air, said witnesses.

Residents living within 2 km of the site have been evacuated and the site has been cordoned off.

Zhao said the extreme heat of the blaze caused by the burning of flammable chemical substances had hindered their work. Fire fighters had risked their lives to take out about 100 barrels of acetone from a neighboring warehouse to prevent the blaze from spreading.

Tests by local environmental departments have showed the warehouse's surrounding water and air environment was not contaminated by the fire.

Police said they were questioning the person in charge of the company regarding the cause of the fire.