ABIDJAN: At least three people were killed and about twenty others were injured during two days of clashes in Ivory Coast's eastern region of Arrah, an official and residents said on Tuesday.

The violence was sparked by frustrations over the continued policing of the area by former northern rebels and degenerated into ethnic clashes, underscoring security challenges faced by President Alassane Ouattara, almost a year after taking office.

"Calm returned last night and it stayed calm thanks to reinforcements from the United Nations soldiers," said Jean Bouadou, mayor of the town of Arrah, about 210 km (130 miles) from Abidjan.

"There are three dead - two from bullet wounds and one from machetes - and about twenty injured," he added.

Locals were protesting against former rebel FRCI soldiers - who helped bring Ouattara, a northerner, to power during last year's post-election conflict - rather than gendarmes providing security in the region.

Residents said violence then broke out between Agni, an ethnic group from the area, and northern Malinke people.

Copyright Reuters, 2012