If Pedro Baños is the source, then it's certainly not true.IMPORTANT: French and British soldiers killed in Ukraine! “I asked for confirmation and they told me that it is accurate. So, the Russians carried out an attack on Odessa, which killed 18 members of the British Special Air Service and injured 25 more. And they tell me that French soldiers died, not mercenaries who are French, no, these are soldiers of the French army. They were killed in large numbers.” — Colonel of the Spanish Army Reserve Pedro Baños
Pedro Baños is a well known ultra-far-right pro-russian conspiracy-theorist. Many in Spain even consider he is a propagandist at the service of the Kremlin.