Rwanda has deployed what it called a protection force to the Central African Republic following attack on its peacekeepers there by rebels advancing to the capital, Bangui.
The Rwandan and Central African Republic governments have accused ex-President François Bozizé, who has been barred from presidential election due on Sunday of backing the rebels and plotting a coup.
The former Head of State has denied the accusation.
UN peacekeepers have said the rebel advance has been halted while AFP news agency quotes a CAR government spokesman as saying that Russia has also sent several hundred soldiers and heavy weapons to the country to support the government.
BBC