PARIS—France may introduce stricter coronavirus restrictions for British visitors when tourism reopens this summer to prevent the spread of a virus variant first detected in India and causing concern in Britain, authorities said Sunday. The possibility of tighter restrictions for British tourists was raised Sunday by Foreign Minister Jean-Yves Le Drian. The minister suggested that Britain could be put in a health category of its own, somewhere in between the strictest measures that France is imposing on visitors from India and 15 other countries, and more relaxed requirements being readied for visitors from the European Union and some other countries. Without giving specifics, Le Drian said “health measures that are a bit stronger” could be applied for British tourists. The minister indicated that the government in Paris is watching how the situation develops before making up its mind. “We hope that the variant can be controlled in a country which …