KHARTOUM, Oct 1 (Reuters) - A Sudanese army officer has said his forces had inflicted heavy casualties on rebels fighting to gain control of a key southern town, Sudanese state television reported late on Wednesday.

Major General Adam Hamid, commander of the Equatoria military area, told the television his forces had seized and destroyed several tanks in fighting at the Khor Inglis bridge which is a few miles west of Torit, a target for the rebel Sudan People's Liberation Army (SPLA).

He did not give any details.

Aid workers said the SPLA began shelling the area around Torit this week and that there were battles around the bridge.

The SPLA, fighting a 15-year civil war, has said little about the fighting.

Torit lies 140 km (87 miles) southeast of Juba city, a prime target for the SPLA which wants autonomy of the mainly Christian, animist south from the Moslem, Arabised north.

Justin Yaac, Nairobi representative of the SPLA and its political wing the Sudan People's Liberation Movement, said Torit was one of a number of towns the SPLA is targetting in its drive to "obliterate all defences around Juba."

On Wednesday, state television showed Interior Minister Abdel Rahim Mohammad Hussein touring Torit and saying that the town will be "a graveyard for the invaders".

Hussein was the first senior official to visit the town since fighting erupted in Eastern Equatoria state on September 14 and his trip was apparently aimed at dispelling rumours that the town had fallen into rebel hands.

Sudan says southern neighbour Uganda is fighting alongside the rebels in Eastern Equatoria, a charge Kampala denies.

This week, it ordered a general mobilisation to confront what it called an attack by Uganda, backed by Eritrea and Rwanda, in southern Sudan. It was the first time the government declared a nationwide mobilisation since January, 1997.

Aid agencies said the Sudanese government has launched an extensive campaign of aerial bombardment in the southern part of Eastern Equatoria close to the Ugandan border.

Khartoum has previously accused Uganda, Eritrea and Ethiopia of assisting the SPLA, a charge the three countries have in the past denied.