Fuel supplies for Ethiopia's hard; pressed armed forces are arriving in Addia Ababa despite a rebel attempt to cut the capital's road to the Red Sea, diplomatic sources said today.

The sources in Addis Ababa said that despite the loss of a bridge on the road to the port at Assab, where the government has an oil refinery, truck convoys have made their way to the capital with only minor delays.

A Somali-backed guerrilla group known as the Afar Liberation Front blew up the bridge last week and it appeared that the capital's fuel supplies might be endangered. The sources said convoys are crossing a nearly dry river bed.

Meanwhile, Ethiopian and Somali forces are massing at opposite ends of the strategic Marda mountain pass for what informed sources believe could be a decisive battle.

The pass leads from the arid Ogaden region into Ethiopia's highland center. If the Ethiopians complete their buildup first, they are likely to launch a counter assault into the Ogaden, which has been largely captured by the Somalis, the sources said. The Somalis may try to storm the mountain fortress towns of Harar and Dire Dana, which they say belong to the Somali people.