Fighting has increased since clashes at the weekend in which a South African soldier, along with three Tanzanian troops, was slightly injured in an M23 mortar attack.

More than 1000 soldiers from 6 SA Infantry Battalion, based in Eastern Cape, are part of the UN's 3000-strong intervention brigade, which is backing a DRC government forces' assault on rebel positions.

The brigade has an aggressive mandate and the power to pursue, engage and disarm the M23 rebels, who are heavily armed and backed by tanks. It is believed that their arms and other munitions are being supplied by Rwanda, a claim that country vehemently denies.

A South African soldier said yesterday that teams of Special Forces members had been engaging the rebels.

"The engagements occurred as helicopters attacked M23 supply lines between Goma and Rwanda. Our snipers were specifically targeting rebel command-and-control posts. It appears from information coming from the front that the officers were busy planning attacks on DRC and UN bases," he said.

The national secretary of the SA National Defence Union, Pikkie Greeff, confirmed the involvement of snipers: "Our sources in Goma have revealed that at the time of attacks [on M23 supply lines] by UN Ukranian Mi24 attack helicopters, snipers from our Special Forces were engaging the rebels. They have killed a number of rebels, with reports of one being shot from a distance of 2.2km."

He said at least one South African soldier was shot in the leg.

"Information is sketchy. The soldier is in a stable condition and was evacuated to hospital."

Greeff said the fighting was in an area known as Kigali Towers - 15km from the North Kivu provincial capital, Goma - where M23 rebels had dug in.

"[Our information is] that within the next two weeks SA Air Force Rooivalk attack helicopters are to be deployed to join the clashes . they will provide much-needed fire power to be used to drive the rebels from their positions," he said.

M23 president Bertrand Bisimwa said yesterday: "There was a big offensive this morning . It was the UN that was shooting at us, from their helicopters. It's the Tanzanian and South African troops that are on the frontline. It's them we see first."

The intervention brigade was created after the rebels briefly held Goma late last year. Then UN peacekeeping forces stood by and did nothing because they were authorised only to protect civilians.

SANDF spokesman Brigadier-General Xolani Mabanga confirmed that a South African soldier had been slightly injured. - Additional reporting by Sapa-AP