At least four people were confirmed dead and 19 others were injured in Monday morning\'s explosion in Xi\'an, capital of northwest China\'s Shaanxi Province. The accident happened at around 7:30 a.m. at Jiatian International Mansion, a commercial building in the outer Gaoxin District, a spokesman with the city\'s fire prevention bureau said. He said the victims had not been identified, and the injured were being treated at the Gaoxin Hospital and the Provincial People\'s Hospital. Xinhua reporters at the scene were unable to approach the building, as fire control authorities had sealed off the area, fearing that further blasts might cause more casualties. It was unclear where or why the explosion happened, but a witness claimed it was a natural gas explosion in a restaurant on the first floor. The explosion blast away a sign board at a nearby bus stop and damaged many cars. Broken window panes were seen two to three kilometers from the site.