Ugandan rebel forces advanced to the outskirts of Kampala today and an army barracks in the capital was reported shelled.

The developments came a day after Government soldiers went on a rampage in which six people, including four schoolchildren, were killed.

A source in Uganda’s military Government said guerrillas from the National Resistance Army had moved to within three miles of Kampala from positions farther to the southwest.

Foreign Minister Olara Otunnu of Uganda said at a news conference here today that in the last six days the National Resistance Army rebels had mounted an eight-pronged offensive in an attempt to wreck their peace agreement with the Government. The pact, signed Dec. 17, was designed to end a five-year-old civil war.

Uganda announced today that it was offering the country’s main guerrilla group an equal say with the army on the governing military council and vice chairmanship of the body.

The Government called the offer today to the National Resistance Army proof of its commitment to end a four-and-a-half-year civil war that has killed, displaced or maimed thousands of people in the East African nation.

The proposals were outlined in a statement issued in Nairobi and broadcast over the Ugandan radio at the opening of the fourth round of peace talks. Uganda’s military leader, Lieut. Gen. Tito Okello, and the commander of the insurgents, Yoweri Museveni, led their delegations.

General Okello arrived in Nairobi this morning to take command of the delegation from his Defense Minister, Col. G. Wilson Toko, who led the Government side in previous sessions. Mr. Museveni had not taken part since the first two rounds in late August and early September.

The guerrillas are the largest and best organized of several bands of insurgents who began fighting the civilian Government of President Milton Obote early in 1981.

Seventeen Government soldiers have been killed and 82 captured in clashes at Katonga Bridge, 60 miles southwest of Kampala, rebels said today.

A spokesman for the National Resistance Army said there had been no casualties on the rebel side in fighting at the bridge over the last few days.

The guerrillas, who are fighting Uganda’s new military Government, will hold onto Katonga Bridge, the rebels’ eastern front, at all cost, the spokesman said by telephone from Masaka, the country’s third largest town.

The bridge is on the road that links Kampala to Masaka, which has been cut off by the rebels for three weeks.