The three-week-old uprising by SELEKA rebels poses the biggest threat yet to President Francois Bozize's near ten-year rule over the former French colony a nation plagued by poverty and turmoil despite its rich natural resources.

Regional neighbours agreed on Friday to send more troops to shore up CAR's army after a string of defeats and after French President Francois Hollande rejected a plea for military help made by embattled President Francois Bozize.

Insurgents riding motorbikes and packed into pickup trucks streamed into Sibut, a regional capital on a major crossroads about 190 kilometres (115 miles) north of the capital Bangui, unopposed early on Saturday, said witnesses.

Center>Copyright Reuters, 2012