By Alastair Macdonald and Philip O'Connor

LILLE, France (Reuters) - French riot police charged and used tear gas to disperse rowdy English soccer fans in Lille on Wednesday, though the northern city was spared feared clashes with Russian supporters.

Throughout the day, police said, 36 people were arrested for various offences as Russia lost to Slovakia in Lille and England prepared to play Wales in the same Euro 2016 group in nearby Lens on Thursday.

There had been fears of violence in the north between Russian and English fans after they had clashed when their teams met in the southern city of Marseille on Saturday.

In the event, few Russians were in evidence on the streets of Lille after their team's 2-1 defeat in an afternoon fixture and the main trouble in the evening was caused by English fans chanting outside bars in groups of up to 200, watched by police.

After dark, as the ancient center of Lille filled with local people streaming home from a screening of the French team's victory over Albania, confrontations between small groups of supporters prompted riot forces to intervene, chasing fans along streets, using pepper spray, dog handlers and acoustic grenades.

There was little physical violence and the authorities said only 16 people involved in some way in the European soccer tournament were treated in Lille hospitals throughout Wednesday.

A game of cat-and-mouse, as England supporters moved on to gather elsewhere and sing defiantly at police, eventually broke up in the small hours as fans drifted off in anticipation of the game against Wales in Lens at 3 p.m. (1300 GMT) on Thursday.

Violence in the Mediterranean port of Marseille before and after England's 1-1 draw with Russia, including a charge in the stadium by Russian fans after the final whistle, has seen the hosts of the 2018 World Cup warned by organizers UEFA that the country's team will be disqualified if there is a repeat of such disorder.

Reuters journalists saw at least three Russians detained by police in Lille before the match, apparently after having been identified as suspects in the Marseille trouble.

During the game against Slovakia, a flare went off in the stands among Russian supporters after Russia scored late on to give the team's fans hope of salvaging a draw. But UEFA officials indicated that the incident would not trigger disqualification.

UEFA also warned England that a repetition of fans' violent behavior could see the team expelled. There was no immediate reaction from UEFA, European soccer's governing body, to the events in Lille, where police said they had "saturated" the city with nearly 4,000 officers and limited alcohol sales.

England fans complained that the police had been heavy handed. "Shame," some shouted at the heavily armored forces.

However, the authorities had clearly decided to hold back from making mass arrests among noisy and disruptive groups.

(Additional reporting by Pierre Savary and John Irish; Writing by Alastair Macdonald; Editing by Bill Rigby)