Private broadcaster TBS reported that a "considerable number" of people were feared dead inside the mall in the town of Kashima after the fire brigade said that the second floor collapsed in the 7.1-magnitude tremor on Tuesday afternoon.As night fell, regional officials said they believed 10 people were unaccounted for in the mall, public broadcaster NHK reported. It earlier cited police as saying between 20 and 30 of the mall's employees could not be contacted.Police told AFP earlier that they could not confirm any fatalities inside the badly damaged building. Kyodo News reported that four people had been taken to hospital, all of them conscious.Prime Minister Takaichi Sanae late Tuesday pledged that emergency responders would work "tirelessly" through the night "starting with the rescue and lifesaving of those affected."Multiple people were also believed to be unaccounted for at a factory in Yatsushiro city where the tip of a chimney fell down, NHK reported, citing sources.One person was killed when a house collapsed during the quake, Kyodo reported.NHK aired footage from elsewhere in the southwestern Kumamoto region on Kyushu island showing several blazes, damaged bridges, a derailed cargo train and a number of houses threatening to topple over.The tremor at 4:27 pm (0727 GMT) had a magnitude of 7.1, the Japan Meteorological Agency (JMA) said, but reached the highest level of seven on Japan's Shindo scale.The US Geological Survey put the magnitude at 6.8.A succession of aftershocks followed, including one with a magnitude of 6.1 at 5:08 pm.Hundreds of earthquakes strike Japan every year, but the vast majority cause little damage.Power outages, firesChiharu Hara, a 35-year-old recruitment agent who was in Kumamoto, told AFP that she was "terrified" when the quake struck."The office swayed violently side to side. I was afraid it would collapse. Everyone panicked," Hara said.Footage verified by AFP showed heavy vehicles, street lights and traffic lights swaying vigorously for about twenty seconds.Elsewhere, vehicles on a two-lane road in the province carefully navigated sections of buckled pavement.Many roads were closed and high-speed shinkansen train services were suspended in the region affected by Tuesday's quake. Kumamoto airport was closed for several hours before re-opening in the evening.Two hospitals reported taking in at least 50 injured patients each, NHK said."People are coming in with burns and fractures from being trapped under objects due to the earthquake, and ambulances are constantly bringing in injured people," NHK quoted one hospital employee as saying."Inside the hospital, there are water leaks and electrical system failures."The broadcaster also said that around 10 people were hurt at a nursing home for the elderly.