Opponents and supporters of the Democratic Republic of Congo President Joseph Kabila traded accusations of electoral violence on Monday as tensions rose three weeks before a crucial presidential vote.
The pro-Kabila coalition said opposition supporters attacked a march over the weekend, injuring dozens while opposition leader Felix Tshisekedi's UDPS party said police detained more than 40 of his supporters in 48 hours.
Western powers are closely watching the December 23 election in the former Belgian colony that has never seen a peaceful transition of power since its 1960 independence.
Under international pressure, President Kabila agreed to step aside, but critics worry he will engineer a victory for his handpicked successor, former Iinterior minister Emmanuel Ramazani Shadary.
President Kabila's FCC coalition said "young delinquents, drug addicts who are UDPS supporters" attacked a march for Ramazani Shadary supporters on Saturday in Mbuji Mayi in Eastern Kasai Province.
"We have 35 seriously injured and with fractures," an FCC statement said.
East Kasai governor Alphonse Ngoyi Kasanji said on Monday there were 15 wounded treated at a local hospital.
A source at Mr Tshisekedi's Union for Democracy and Social Progress or UDPS party said police had encircled its headquarters in Mbuji Mayi between Sunday night and Monday morning and had detained dozens of his supporters over the weekend.
"Around 20 of our activists were arrested on Saturday and are still in police custody. One of our parliamentary candidates is still reported missing," said regional UDPS representative Denis Kalombo told AFP.
Mr Vincent Ngoyi, a local official, said police had been deployed to the UDPS headquarters in the region for "security reasons" because they were responsible for unrest on Saturday.
Tens of thousands of supporters turned out to welcome Mr Tshisekedi, whose father Etienne was the face of DR Congo opposition for decades, as he returned to Kinshasa last month to kick off his campaign to replace President Kabila.
Meanwhile, clashes between the army and rebels loyal to a renegade former general in eastern DR Congo have killed at least 18 people, military sources said Monday.
Fighting killed 14 rebels and four soldiers in Fizi, a region of South Kivu, a mineral-rich province which is prone to ethnic tensions, the sources said.
The unrest is another front by rebels opposed to President Kabila as the coujntry prepares for a much-delayed presidential election on December 23.
The military sources said one soldier and two rebels were killed early Monday in fighting.
Earlier, regional army spokesman Captain Dieudonne Kaserek, told AFP 12 rebel fighters had been killed including a deputy commander known as Alida. He said three of the soldiers drowned in a river during combat.
The clashes pit the army against rebels loyal to a former army general, William Amuri Yakutumba, who is opposed to President Kabila.
The militia is allied to rebels of the National Liberation Front based in neighbouring Burundi, according to several regional sources.