President Asif Ali Zardari has said that 9th May will always be remembered as a dark day in country's history, when a politically instigated mob ran amok across the country, damaging public property and military installations.In a statement, he condemned the violence and said that the unfortunate incidents severely tarnished the country's image, which only served the interest of Pakistan's enemies.He termed the mob attacks as an attempt to challenge the writ of the state.The President expressed pride in Pakistan's armed forces and the institutions.He emphasized that those responsible for the May 9 violence should be held accountable according to the law.Source: Radio Pakistan