The U.N. Security Council called on Eritrea Tuesday to immediately withdraw troops and tanks from a buffer zone established after a 2 1/2-year border war with Ethiopia and urged both countries to refrain from any threat or use of force, according to AP. Hedi Annabi, the assistant secretary-general for peacekeeping, told the AP after briefing the council that Eritrea's movement of 1,500 troops and 14 tanks into the area on Monday morning was «the most serious violation» of the zone since the Horn of Africa neighbors signed a peace agreement in Algiers, Algeria in December 2000. U.N. spokesman Stephane Dujarric said «we understand the troops that had entered are still there.» Security Council members expressed deep concern at Eritrea's violation of the cease-fire agreement and called on Eritrea «to immediately withdraw its troops from the Temporary Security Zone» which is 15 miles (24-kilometers) wide and 1,000-kilometers (620-miles) long. «Members of the Security Council call on both parties to show maximum restraint and to refrain from any threat or use of force against each other, to avoid any action which may lead to an escalation of the tension between the two countries and to adhere to previous commitments they have made,» the council's statement said. Japan's U.N. Ambassador Kenzo Oshima, the current council president, told reporters after reading the statement that «we do not believe that that action, although deplorable, is immediately going to lead to war.»