Fighting took place in central Lubumbashi near the seat of the assembly for Upper Katanga province, the reporter said.

The clashes occurred two days ahead of elections for the province's powerful governor, who is chosen by members of the assembly.

Police "restored order" and sealed off the building, a local police commander said.

Governorship elections in the Democratic Republic of Congo's 26 provinces should have been held on March 26.

But they were postponed by Tshisekedi, who demanded a probe into alleged vote-buying among provincial delegates who had also elected the country's Senate.

Tshisekedi, 55, took the helm from Kabila on January 24 in the vast country's first peaceful transition of power.

His election on December 30 was marred by allegations of widespread fraud, although the international community quickly backed his mandate in an effort to avoid conflict.

Kabila's supporters hold a huge majority in the National Assembly and provincial assemblies, hampering Tshisekedi's campaign-trail promises to forge ahead with electoral and economic reform and launch an anti-corruption drive.

Campaigning for the governorship elections officially began on Saturday and was to close at midnight on Monday. The voting takes place on Wednesday.