Story highlights The arrests come after an unruly crowd breaks away from main the protest

Dozens are arrested for various offenses, including obstructing police

At least 143 people were arrested in London following protests over elections in the Democratic Republic of the Congo, British authorities said.

The arrests came after an unruly crowd broke away from main protest.

"A group moved away from the main protest and began to damage property, including cars and shops as well as threatening members of the public," the Metropolitan Police said in a statement late Saturday.

Dozens were arrested for various offenses such as obstructing police and blocking a highway, police said.

Congolese President Joseph Kabila won re-election last week, and supporters of his main frontrunner have decried the outcome as rigged.

Etienne Tshisekedi, the main challenger, warned that the opposition would not accept the election outcome amid claims of ballot stuffing and manipulated voter lists.

The nation's communications minister has asked citizens who contest the results to do so in court.