"The military commander at the front said the town was liberated at 1445 (1245 GMT). He said the enemy had crossed the river and we are looking for boats so that we can pursue them," Mr Kabila told a news conference in the eastern town of Goma.
The fall of Zaire's third largest city, that housed the army's headquarters for operations in the eastern war zone, deals a severe blow to the government of President Mobutu Seke Seko.
Kisangani residents contacted from Kinshasa said Zaire soldiers fled late on Friday and early yesterday. "They left . . . after looting what they could in the short space of time that they had." one resident said. Another said rebels had gathered in the city centre and residents were coming out to welcome them.
Before announcing the fall of the city, Mr Kabila had talks with the United Nations envoy Mohammed Sahnoun in Goma. Mr Sahnoun is trying to mediate an end to the fighting.
The fall of Kisangani is the biggest setback for the government since the rebels took up arms in October, vowing to topple Mr Mobuto. They now hold up to a fifth of the country.
Diplomats said resistance apparently crumbled after soldiers of Zaire's notoriously undisciplined army went on a looting spree in the city and then fled across the Zaire River.
"What happened looks distinctly like a betrayal," a senior government official said, commenting on fighting between Serb mercenaries and soldiers at the international airport on the outskirts of Kisangani on Friday.
France sent a plane with an escort of 30 paratroops from its base in neighbouring Central African Republic to Kisangani and successfully airlifted out 15 foreign nationals.
Prime Minister Alain Juppe ruled out any unilateral military intervention by France.Reuse content