NAIROBI, May 24 (AFP) - Ethiopia and Eritrea each reported Monday that their troops had killed or wounded hundreds of the enemy in a battle lasting for three or four days, on the western front of their border war. Each side said it had won, and accused the other of having gone on the offensive. Eritrea claimed to have shot down a helicopter gunship. In Addis Ababa, the Ethiopian government issued a statement saying the fighting started on Saturday, with four Eritrean brigades (about 12,000 soldiers) attacking Ethiopian positions near the Mereb River, on the eastern salient of the western front. It said the Ethiopian troops repulsed the attack on Monday after killing more than 400 Eritrean soldiers and wounding more than 1,500. "The Ethiopian defences forces successfully repelled the attack," it said, adding that the Ethiopian forces had captured "heavy and light armament," but giving no figures for Ethiopian casualties. Ethiopian aircraft took part in the action, causing "heavy losses to the Eritreans," it added. But Eritrean presidential chief of staff Yemane Ghebremeskal told AFP by telephone from Asmara that the Ethiopians had attacked in division strength (about 7,000 to 11,000 men) on Friday. The main battle lasted until Sunday, he said. "They tried again today (Monday), bringing in two helicopters," he said. "Our troops shot one down -- an MI-35 -- and the fighting soon died down." During the four days of fighting, Ghebremeskel said, "our troops killed 380 Ethiopian soldiers, wounded 975, and captured 11." Ghebremeskel said he had no precise figures for Eritrean casualties, but characterised them as "very light," because, he said, it was the Ethiopians who had gone on the attack. He said the Eritrean force on the Mereb River was probably somewhere between one and three 3,000-strong brigades. In Asmara, meanwhile, Eritreans on Monday celebrated the eighth anniversary of their capture of the capital at the end of their 30-year war of independence from their huge neighbour, when they joined with Ethiopian Tigrayan rebels to overthrow Ethiopian dictator Mengistu Haile Mariam. Ghebremesekel said the residents of the capital celebrated with music, dances, acrobats, soldiers showing the flag, and an overflight by the Eritrean air force. The two Horn of Africa neighbours first went to war over the ill-defined border in May last year. Fighting -- characterised by intense battles interspersed with long lulls -- has continued since. All diplomatic efforts to end the crisis have proved fruitless so far. Both sides have accepted an Organisation of African Unity peace plan which provides for the deployment of peacekeepers and neutral delineation of the 1,000-kilometre (600-mile) -long frontier, but it has stalled because Ethiopia insists that Eritrea must first withdraw from all disputed territory. Eritrea maintains the withdrawal applies only to the Badme region on the western front, which Ethiopian troops reoccupied in February after fierce fighting which both sides say left thousands dead. The diplomatic efforts continue.  