ANTOINE ROLLAND RWANDA and Russia have sent troops and supplies to the Central African Republic to help counter a surge in violence by rebel groups ahead of Sunday's election, officials and a security source in Bangui said. Security forces and U.N. peacekeepers have been battling rebels who have occupied towns and roads outside the capital. The authorities accuse former president Francois Bozize, whose presidential candidacy was rejected by the courts, of plotting a coup with several militant groups. A spokesman for Bozize's KNK party has denied the accusations. President Faustin-Archange Touadera, who is seeking re-election, came to office in 2016…