N’DJAMENA, Chad (AP) — Rebels are threatening to depose the son of Chad’s slain president after he was named interim leader of the central African nation. The rebel group that the military blamed for President Idriss Deby Itno’s death said its forces were advancing on the capital of N’Djamena. Its statement raises the specter of a potentially violent power struggle in the city of 1 million people. Uncertainty prevailed early Wednesday as to whether the military would remain loyal to Mahamat Deby Itno in the aftermath of his father’s death. Chad’s military spokesman said Tuesday that the president who had been in power for three decades died during a visit to the front lines of the battle against the rebel group.