KINSHASA (Reuters) - Congo's army accused rebels of shelling a border town on Monday and said it showed the M23 group's declaration of a ceasefire over the weekend was worthless.
The rebels, however, said government forces had attacked their positions in the steep, forested hills along the Ugandan frontier with heavy weapons fire on Monday morning.
"This is not fighting, it is bombs launched by M23 targeting the population of Bunagana," Congo army spokesman Colonel Olivier Hamuli said by phone.
"They are targeting civilians. The call for a ceasefire was a lie," Hamuli said, adding Congo's military would pursue the rebels.
The army has in recent weeks expelled M23 from towns they had occupied across eastern Congo, making mediators hopeful of a deal to end the conflict.
However the latest violence, which comes as South Africa hosts leaders from the Great Lakes region and southern Africa to try to push the peace process forward, underlines the gulf that remains between the Kinshasa government and the rebels.
Uganda said some of the artillery launched from inside Congo had landed on its territory but that it was still unclear who had fired the shells.
An U.N. aid worker on the Ugandan side of the border said thousands of residents were fleeing the area.
"We were 4 km from the border and the explosions were so bad we had to pull back. The streets are full of people running from the fighting," said the U.N. refugee agency's representative in Uganda, Lucy Beck.
(Reporting by Pete Jones in Kinshasa and Elias Biryabarema in Kampala; Writing by Richard Lough, editing by Elizabeth Piper)