BELGRADE — THE Yugoslav Army has agreed to evacuate civilians and wounded from the besieged town of Vukovar, where 1,500 Croatian defenders are trapped, Croatian radio said yesterday.The national guardsmen are the hard-core end of a Croatian force which has fought an 87-day assault for control of Vukovar on Croatia's border with Serbia. The government in Zagreb admitted Sunday that it had lost the town, which became a powerful symbol of Croatia's resistance to the better-armed Serb-led Army, and asked for the Army's help in saving the remaining 14,000 inhabitants, who have been trapped underground by the fighting. Croatian radio said International Red Cross and European Community observers would supervise the evacuation of the wounded from Vukovar hospital. They were expected to be evacuated by boat on the Danube River. Croatia wants to take its evacuees to the nearby town of Vinkovci, which it still controls. The Serb-led Army has suggested they should be taken first across the Danube to Serbia. The final route and the timetable of the evacuation are being negotiated. An EC-brokered cease-fire, the 13th to date, came into effect Saturday, but only temporarily dampened the fighting. Clashes continued in the eastern region around Vukovar, which has seen bitter fighting, and the Army also launched new attacks yesterday on Osijek, Zadar port, and areas near Dubrovnik, Croatian radio reported. The loss of Vukovar is a severe blow to Croatia after more than four months of war during which a third of its territory has been captured. But diplomats said Serbia had achieved one of its main goals, which could help to speed up a political settlement.