GOMA, Congo -- A Congolese doctor says soldiers and rebel forces suffered heavy casualties over the weekend, as the international community expressed alarm over the escalating tensions between Congo and neighbouring Rwanda.

Dr. Isaac Warwanamiza told The Associated Press that he had seen 82 dead since early Sunday, 23 of whom were government soldiers, the highest death toll reported since hostilities broke out last week.

The doctor said medical services were struggling to cope with the scale of the casualties among government troops and the M23 rebels who launched their rebellion last year.

The front line is only 9 miles (15 kilometres) north of Goma. M23 rebels briefly overtook the city late last year, and Congolese and U.N. troops have been battling to dislodge rebels from heights overlooking the city since Wednesday.