Yes, the French fleet was at the port of Mers-el-Kebir right outside Oran, Algeria. Churchill ordered the British Navy to sink their ships to show that Britain would not make peace with Hitler.

El Kebir's birth name is Abder El Kebir.

British

Yes. The British were worried that the French fleet might be seized by the Germans (even though the fleet had been left out of the armistice treaty) and used against them. Orders had been given by Admiral Darlan, the French naval commander, to sink the boats rather than let the Germans seize them, but that wasn't known to Churchill (that order was obeyed by the fleet in Toulon in 1942, when the Germans decided to invade the rest of France). A French naval squadron in the port of Mers El-Kebir, cannons facing the port, was cornered by mines dropped by English planes and shelled without warning or mercy. 1297 French seamen lost their lives (versus two English seamen). The resentment in France was huge and exploited for years by the Nazis' propaganda.