Police have taken two people into custody while they continue to investigate how fireworks started a blaze that gutted a five-star hotel in northeast China on Thursday.

The pair -- a man surnamed Li and a woman surnamed Feng -- were guests at the Dynasty Wanxin Hotel in Shenyang, capital of Liaoning Province, when the fire destroyed it, said Wang Qingge, spokesman for Shenyang Bureau of Public Security, on Tuesday.

Police investigators suspected the pair had taken two boxes of fireworks to a parking lot at Tower B in the Dynasty Wanxin complex, and set them off 10.8 meters away from the building, said Wang.

However, sparks from the fireworks ignited a plastic lawn on a flat roof on the 11th floor of Tower B and the flames quickly spread, said Wang.

Everyone in the hotel -- about 50 people -- was evacuated and no casualties were reported.

The fire on the first day of the Lunar New Year was China's biggest fireworks accident of this year's Spring Festival celebrations.

The Dynasty Wanxin complex comprises three towers in the bustling Qingnian Street, of Heping District. The fire covered 10,000 square meters in Towers A and B, but left Tower C intact.

The 45-storey Tower A, Shenyang's tallest building, is mainly offices, but includes the five-star hotel. Tower B is mainly apartments.

Wang said the pair could be charged with starting a fire through negligence, which could incur a jail term of three to five years if the fire caused heavy casualties or huge economic losses.

The Shenyang fire department on Tuesday notified business and apartment owners in the buildings to declare their losses in the fire.