UN chief Ban Ki-moon on Tuesday called for restraint and constructive dialogue in Turkey as the country has seen nationwide protests for more than two weeks. The UN chief remained concerned about ongoing clashes between protesters and security personnel, said a statement issued by Ban\' s spokesperson, adding that Ban was saddened by the deaths and injuries during the widespread clashes. \"The secretary-general urges maximum restraint and the pursuit of constructive dialogue in order to resolve differences and avoid further violent confrontation,\" said the statement. \"He believes that stability is best assured through such dialogue and when the rights to peaceful assembly and the freedom of expression are fully respected,\" it added. Nationwide protests began when an environmentalists\' rally aiming to preserve Gezi Park adjacent to Taksim Square in Istanbul met fierce police crackdown, which triggered a wave of fiery opposition against the government\'s policies. Turkish police have detained hundreds of people suspected of involving in violent demonstrations and endangering public order and safety. In the meantime, the ruling Justice and Development Party held two rallies over the weekend in Istanbul and Ankara, attended by hundreds of thousands.