Congo's opposition leader renewed a call Friday for supporters to "terrorise" the country's security forces ahead of November 28 polls and to free opposition activists from jail.
Hours later, Etienne Tshisekedi's supporters clashed with ruling party faithful in the eastern province of Katanga where Kabila was on a campaign tour, leaving six wounded.
In a speech Friday Tshisekedi also stood by comments made earlier this week in an interview in which he urged his supporters to break out political prisoners from prisons across the Democratic Republic of Congo (DRC).
"Any dictatorship is based on fear... The Congolese man must shake the fear and be more self-confident," said Tshisekedi, who served as prime minister under the much-feared former president Mobutu Sese Seko.
"My way of educating the Congolese people is to remove the fear in their heads by mobilising them to terrorise those who have terrorised us for so long... This is not a call for violence," the 78-year-old said.
Tshisekedi issued a 48-hour ultimatum to the government to free detained activists or face an assault by his supporters.
"I give an 48-hour ultimatum to the government to free all our fighters in prison in Mbuji Mayi, Lubumbashi and in Kinshasa," he told a rally.
Mbuji Mayi lies in the country's southern central region; Lubumbashi near the country's southern border with Zambia.Failing that he would call on his supporters to "smash Makala prison" in the capital Kinshasa "to free by force our fighters arrested arbitrarily", he told around 5,000 supporters.
He was speaking in the city of Kisangani, which lies on the Congo river and is the country's third largest, after returning from a trip to South Africa late Thursday.
He had given a phone interview to a Congolese television channel on Monday in which he urged his supporters, calling them his "fighters", to break down prison walls and free their comrades.
According to a rights activist in the Katanga town of Kasumbalesa, Kabila supporters attacked Tshisekedi partisans after hearing they had been tearing up tee-shirts bearing the head of state's portrait.
"Six people suffered stab wounds and two motorbikes were set on fire," Timothee Mbuya said, adding that police broke up the fighting but made no arrests.
Several people were wounded last weekend in street fighting between rival supporters in the mineral-rich province's capital of Lubumbashi.
Tshisekedi's comments have drawn stinging condemnation from the international community.
The European Union, United States, France and the United Nations, which has a large peacekeeping contingent in the DRC, all urged restraint this week and called on all sides to refrain from inflammatory statements.
Tshisekedi denied his comments amounted to incitement.
"Between the one who has Congolese people arbitrarily arrested and killed and me, who is telling the people to take their responsibilities and free their jailed compatriots... who is violating the constitution?" he said.
Tshisekedi, leader of the Union for Democracy and Social Progress, is one of 10 candidates challenging Kabila in the November 28 polls.
He is the last of the candidates by alphabetical order and was assigned the number 11 by the electoral commission.
Tshisekedi had planned a rally on Friday to coincide with a rare numerical sequence in the hour and date -- when clocks showed: 11:11 on 11/11/11 -- seen by numerologists, metaphysicists, phychics as particularly auspicious.
But plans were changed as the plane flying him back from South Africa arrived a day later than expected.