U.N. chief alarmed at Russian plane downing, urges de-escalation

UNITED NATIONS (Reuters) - U.N. Secretary-General Ban Ki-moon on Tuesday expressed alarm at the downing of a Russian plane along the Turkish-Syrian border and voiced the hope that all countries involved in air campaigns in Syria would take steps to avoid such incidents in the future. "He urges all relevant parties to take urgent measures with a view to de-escalate the tensions," U.N. spokesman Stephane Dujarric told reporters. "He hopes that a credible and thorough review will clarify the events and help prevent future recurrences." "(Ban) urges all those who are engaged in military activities in Syria, especially air campaigns, to maximize operational measures to avoid unintended consequences," he added. (Reporting by Louis Charbonneau and Michelle Nichols)