Tokyo: Rescue efforts are underway in Japan after a powerful quake measuring 7.3 on the Richter Scale hit Kyushu region on Saturday killing at least 22 people and injuring over 1,000 others, Xinhua reported. Japanese media however, put the toll at 19. Saturday's shocks comes on the heels of tremors felt on Thursday that left nine people killed in Kumamoto prefecture -- epicentre of both the quakes. Around 20,000 troops were deployed in Kyushu region after the quake struck the region around 1.25 a.m. (local time), The Japan Times reported. Dozens of people are trapped in the rubble of collapsed buildings. Roads have been damaged and landslides have been reported over a wide area. The quake has badly affected the region as around 200,000 households were without power. Extra troops were being sent to Kyushu to help police and firefighters. "We are making every effort to respond," Chief Cabinet Secretary Yoshihide Suga said. There are reports of people trapped inside buildings, including at least 60 inside an old people's home. A village was evacuated on Saturday after a dam collapsed due to the quake, public broadcaster NHK reported. Heavy rain forecast for the coming days could lead to more landslides and affect already damaged structures, Japan's Meteorological Agency said. Saturday's temblor triggered a tsunami advisory, although it was later lifted and no irregularities were reported at three nuclear power plants in the area, a senior government official said. The Kumamoto Prefecture Police said they received reports of 97 people trapped or buried under collapsed buildings. The government also said four apartment buildings near Tokai University in Kumamoto prefecture collapsed and 11 people, including students, were trapped under the wreckage. Prime Minister Shinzo Abe told reporters the government was making every effort to determine the extent of the damage, carry out rescue and recovery, and to get accurate information to citizens. "It's possible that there may be damage over a wide area," Abe said. Gavin Hayes, a research geophysicist with the US Geological Survey (USGS) in Colorado, said the latest earthquake would hamper the earlier rescue operation that was already under way. Japan is one of the most seismically active areas on the Earth, accounting for about 20 percent of global quakes of magnitude 6.0 or greater. It is through bitter experience that Japan has learned the strategies to mitigate damage, injury and death. Not only does it implement some the best building construction practices but it has also established an early warning network. The meteorological agency initially said the Saturday quake measured 7.1 on the Richter Scale but later revised it up to 7.3. Several aftershocks rattled the region later Saturday, including two of nearly magnitude-6, and experts warned of more.