Rescuers are racing against the clock to reach survivors trapped under the rubble of a school in Mexico City. <br /><br />The search which has stretched into a new day includes that of a 12-year-old girl believed to be sheltering under a table.<br /><br />At least 21 children and five adults died as the school collapsed, several are still missing.<br /><br />Throughout the night, teams of professionals and volunteers frantically picked away at the unstable debris to try to reach her.<br /><br />The 7.1 magnitude quake hit central Mexico on Tuesday. <br /><br />Dozens of buildings across the region collapsed. At least 230 people are now known to have died, more than 2000 others were injured.<br /><br />President Enrique Peña Nieto has declared three days of mourning for the victims.<br />
