The army was asked to be on standby and curfew continued in parts of Meghalaya's capital Shillong for the third day on Saturday after night-long violence during which a mob burnt a shop, a house and damaged at least five vehicles besides injuring a senior police officer. At least 500 people have been given shelter in an army cantonment, a Defence Ministry spokesperson said. Chief Minister Conrad K Sangma, who chaired a high-level meeting on Friday, has appealed for calm.