With logistical and co-ordination support from Britain, the pro-government troops have moved forward along a key road between the towns of Waterloo and Masiaka, that leads to the capital.
A joint force of Sierra Leonean soldiers and Nigerian UN troops has advanced about 30km from positions they held on Thursday.
The government advances come as the British Chief of the Defence Staff, General Sir Charles Guthrie, prepares to visit Freetown this weekend.
Honour the dead
Earlier, state funerals had been held for the 19 people killed on Monday outside the house of the rebel leader, Foday Sankoh.
At least 10,000 mourners gathered at the National Stadium, in Freetown, to honour the dead, who the government described as national martyrs.
They were killed when thousands of peace demonstrators gathered outside Mr Sankoh's house to protest against the rebels' continued detention of the 500 UN peacekeepers.
RUF fighters fired into the crowd, killing at least seven people; others died in the fighting and confusion that followed.
The rebel leader disappeared after the fighting.
Friends and relatives of the dead wept and threw themselves to the ground in grief as the coffins, draped in Sierra Leone's national flag, were driven into the stadium.
One woman, Mary Lake, whose son and foster-son had been killed by the rebels, cried: "Let Foday Sankoh face the international [criminal] tribunal!"
President Kabbah told the mourners that the 19 had died for freedom and democracy.
"We must make sure that we do not forget the principles for which they died," he said.
'Window of opportunity'
With the confrontation between United Nations troops and rebels continuing, British officials say that extra UN troops will be flown into Sierra Leone over the next few days.
They say battalions from Jordan, India and Bangladesh will bring the UN force up to its planned strength of more than 11,000 troops, from its current level of 8,900.
The RUF rebels are estimated to number some 15,000 fighters in all.
BBC defence correspondent Jonathan Marcus says the view in London seems to be that the window of opportunity seized by Mr Sankoh may now be closing.
Three-hour battle
Meanwhile news has emerged from southern Sierra Leone of a three-hour battle between UN peacekeepers and Revolutionary United Front rebels.
According to civilians who fled the latest fighting on the main road between Freetown and Bo, the RUF attacked on two fronts, but were beaten back by the Guinean UN troops fighting alongside pro-government militias.
Truckloads of pro-government reinforcements were seen heading for the area, near a town called Mile 91.