At least 11 people were killed in DR Congo on Tuesday as clashes erupted during protests against President Joseph Kabila who is refusing to leave office as his mandate ends, officials said.

Nine people died in Kinshasa during protests to demand that President Kabila step down, a government spokesman said, while a protester and a policeman were killed in the second city Lubumbashi according the region's governor.

"In Kinshasa there were nine dead, not a single one more," said Mr Lambert Mende, the government's chief spokesman.

The UN's mission in DR Congo, MONUSCO, had earlier said it was probing reliable reports that around 20 people had been killed in the country's capital during protests.

Governor Jean-Claude Kazembe said that along with the two fatalities in Lubumbashi, three people had been hurt in clashes.

President Kabila appears determined to cling on to power, and tensions in DR Congo have been running high, with police massing in the cities and many people staying home to avoid violence.