By Mitch Phillips

MARSEILLE, France (Reuters) - Violent clashes between English and Russian soccer fans broke out in the southern French city of Marseille on Saturday ahead of the two countries' opening Euro 2016 match, leaving at least one person critically ill in hospital.

Riot police fired volleys of tear gas and deployed water cannon trucks to break up several skirmishes in the narrow streets of the city's Vieux Port (Old Port) and outside the Velodrome stadium.

There were also scuffles between visiting fans and locals, with some wielding cafe tables as weapons.

European soccer's governing body, UEFA, condemned the violence. "People engaging in such violent acts have no place in football," it said in a statement.

Marseille's emergency services said 15 people were injured during the fracas, including one middle-aged man who was knocked unconscious, and one England supporter who suffered a heart attack.

By Saturday evening, tens of thousands of fans had descended on Marseille ahead of the evening's match. Broken glass and debris littered some roads and alleys near the waterfront, the focal point of clashes between English, Russian and French fans.

Water cannon trucks and scores of police armed with batons and shields positioned themselves between rival groups of fans as they headed toward the 67,000-capacity arena.

The clouds of tear gas produced images of unrest all too similar, though on a much smaller scale, to those in the city 18 years ago when violence flared for two days and nights around England's World Cup game against Tunisia.

Local police chief Laurent Nunez said about 300 English fans had been involved and a similar number of Russians. There were no plans to close a beach-side fan zone, he said.

Police made six arrests on Saturday, adding to the nine from Friday. Those charged could face trial as early as Monday.

There are designated separate routes to approach the Stade Velodrome for the match while the fan zone has been split into two sections, each holding 40,000.

(Additional reporting by Antonio Denti and Jean-Francois Rosnoblet in Marseille and Dominique Vidalon and Chine Labbe in Paris; writing by Richard Lough; editing by Janet Lawrence and Dominic Evans)