Yaounde - Three people were killed when Central African Republic rebels attacked a Cameroon border post on Sunday in an attempt to free comrades held in the neighbouring country, the Cameroon state broadcaster said on Tuesday.
CRTV said the rebels opened fire after a police officer tried to stop them from entering Cameroon, killing him and a boy who was manning the frontier gate in Garoua-Boulai, some 600 km (372 miles) east of the capital Yaounde.
"Two people were killed by the rebels, while one rebel was killed and two others were arrested after Cameroon special forces counter-attacked," CRTV said.
The attack was the first time rebels from the Central African Republic used deadly force in an incursion into Cameroon, which has managed until now to avoid the conflicts that have engulfed its neighbours in the central African region.
Central African Republic is struggling to tame several rebel groups opposed to President Francois Bozize, who came to power in a 2003 coup and has faced low-level insurgencies since 2005.
The government in Bangui signed a peace deal with one of the last rebel groups in August.
It hopes now to concentrate its efforts on fighting Ugandan Lords Resistance Army (LRA) rebels, led by a self-styled mystic prophet Joseph Kony, who has carried out several attacks in the Central African Republic in recent months.