At least 21 people were injured and dozens of buildings collapsed when a shallow 5.4-magnitude earthquake struck eastern <a href="https://www.thenationalnews.com/tags/china/" target="_blank">China</a> in the early hours of Sunday, state media reported. The quake occurred at 2.33am local time about 26 kilometres south of the city of Dezhou in Shandong province, at a depth of 10km, the US Geological Survey said. Videos posted on social media showed shaking light fixtures, trembling ground and people fleeing their buildings. "The tremor was so strong... during the earthquake my head was shaking on the pillow, I thought I was having a nightmare," one person posted on social media platform Weibo from Shandong's neighbouring Hebei province. The USGS's Pager system, which provides preliminary assessments on the impact of earthquakes, issued a red alert – estimating extensive damage and some casualties were probable based on previous quake data. Citing Shandong authorities, state broadcaster CCTV said there were at least 21 injured and 126 houses or buildings had collapsed from the earthquake, which was followed by 52 aftershocks. China's Ministry of Emergency Management launched a level four emergency response and sent a team to Shandong province to lead the rescue work, according to state news agency Xinhua. Footage from CCTV showed rescue personnel in red uniforms marching past first aid tents that had been set up on a school athletics field surrounded by seemingly undamaged buildings. "Only specific old dirt buildings that were uninhabited have collapsed," CCTV said, showing footage of piles of crumbled bricks between undamaged buildings and pieces of exterior wall stripped from a still-standing house," the broadcaster said. "Some yard perimeter walls have collapsed and been damaged." Water and communications infrastructure were functioning normally in the area but hundreds of train services were suspended as of Sunday morning, according to CCTV. The quake was felt as far away as the cities of Beijing and Tianjin, as well as in Shanghai, about 800 kilometres from the epicentre. "I can't say anything except that it's scary," another Weibo user said. Earthquakes are not uncommon in China but it is rare for them to hit the eastern part of the country where most of the population and big cities are located. An official from the Shandong Seismological Bureau said the possibility of a larger earthquake is "very small", according to local media.