U.N. Secretary-General Ban Ki-moon Monday condemned the recent capture and detention in Ukraine of observers from the Organization for Security and Cooperation in Europe (OSCE). "The Secretary-General strongly condemns the recent capture and detention of OSCE military monitors as well as a number of accompanying Ukrainian staff," a statement from Ban's spokesman said. "He urges those responsible for their abduction to release them immediately, unconditionally and unharmed." "He appeals to all those with influence to assist in the urgent resolution of this matter," the statement said. The U.N. chief said that international missions working in Ukraine must be allowed to perform their duties without interference. "The Secretary-General urges all parties concerned to take immediate steps to de-escalate the situation in Ukraine. A diplomatic and political solution to this crisis is imperative and long overdue," the statement said. The OSCE monitors were detained last week by pro-Russian separatists in eastern Ukraine. The captives - hailing from Germany, the Czech Republic, Denmark, Poland, and Sweden - were paraded before reporters Sunday and said that they were in good health. A Swede was freed for medical reasons, but the others are still being held. -- SPA 23:29 LOCAL TIME 20:29 GMT تغريد