Islamic State militants have the Euro 2016 soccer tournament in their sights though there is no concrete evidence at the moment of an attack being planned, the head of Germany's domestic intelligence agency has said.

The comments from Hans-Georg Maassen, head of Germany's Federal Office for the Protection of the Constitution, come after France's spy chief said IS militants are gearing up for a campaign of bomb attacks on large crowds in France.

France, where militants last year killed 130 people in coordinated assaults on cafes, bars, a football stadium and a music hall across Paris, will host Euro 2016, which starts on June 10 and runs for a month at 10 stadiums across the country.

"We know that IS has the European Championship in its sights," Maassen told the Rheinische Post newspaper.

He said that while there was no hard evidence of an attack being planned, there was "quite a lot of background noise, an elevated number of indications" that IS, al Qaeda or its Syrian affiliate Nusra Front wanted to perpetrate attacks against Western targets.

About 2.5 million spectators are expected for 51 soccer matches involving 24 teams at Euro 2016. There will also be "fan zones" for crowds watching games on big screens in major cities. – Reuters