Guy Simplice, a spokesman for president Michel Djotodia, said there had been heavy fighting near the seat of government in the capital Bangui before the army was able to repel the aggressors.
Although the attackers could not immediately be identified, there have been rumours a Christian militia, believed to be backed by the president ousted by Mr Djotodia in a coup nine months ago, would attempt to seize back power.
The heavy arms fire could be heard from the five-star Hotel Ledger where international journalists are staying. A rocket came over the hotel's wall, landing in the grounds and as the shooting died down, helicopters could be heard flying overhead.
The events are the latest indication the poor, but until recently stable nation, is tipping into anarchy.
Earlier, international forces had been sent to pick up truckloads of decomposing bodies of dead Muslims whose remains had been left at a local mosque by relatives.
They were too frightened to be seen burying them in a city where Christian-on-Muslim and Muslim-on-Christian attacks have become a daily occurrence.
Six African Union peacekeepers from Chad were killed earlier this week after their car was attacked in the capital.