Moscow has detained a Frenchman suspected of "purposefully collected information in the field of military and military-technical activities of the Russian Federation". Laurent Vinatier, who works for the Swiss Centre for Humanitarian Dialogue, is also accuded of failing to register as a "foreign agent". The arrest came as French President Emmanuel Macron said pledged support for Ukraine, during a ceremony marking the 80th anniversary of D-Day, in Normandy. "We are here and will not weaken," Macron said in a speech also attended by the Ukrainian president, Volodymyr Zelenksiy and his wife.