A new 44-story luxury hotel in downtown Beijing was engulfed in flames Monday after being showered with sparks from fireworks set off during China's biggest holiday.

There were no reports of deaths or injuries.

The Rem Koolhaas-designed Mandarin Oriental hotel, still under construction, caught fire sometime before 9 p.m. (1300 GMT) as the skies above the Chinese capital were filled with fireworks — part of celebrations of the lantern festival that follows the Lunar New Year.

The shooting flames sent off huge plumes of black smoke and showered the ground with embers. At least seven fire crews were on the scene, and police held back crowds of onlookers and closed a nearby elevated highway to ensure safety.

One onlooker, Li Jian, said he saw smoke rise from the hotel's roof shortly after a huge burst of fireworks showered it with sparks, though it was not clear if the sparks started the fire.

"Smoke came out for a little while, but then it just started burning," Li said.

People answering the phone at the Beijing fire department confirmed the fire but said they were unable to release any details.

Crews had largely exinguished the larger flames about three hours after the fire began, although hotspots continued to flicker.

Beijing usually tightly restricts the use of fireworks downtown, but waives the rules each year during the Lunar New Year holiday. Monday, the final day of the exemption period, marked the first full moon since the Lunar New Year, and massive fireworks barrages exploded in open spaces throughout the city.

The hotel, which had been due to open this year, is next to China Central Television's landmark Z-shaped headquarters, a major prestige project for the city. The television headquarters was not burning. The Mandarin Oriental was expected to be one of Beijing's most luxurious hotels, with 241 guest rooms.

Both buildings were designed by Netherlands architects Rem Koolhaas and Ole Scheeren for the firm OMA. Both were nearing the end of construction.

The fire had destroyed years of hard work, said Erik Amir, a senior architect at OMA, who rushed to the site.

"I think it's really sad that this building is destroyed before it can be opened to the public," he said.