The governments of Germany, France and the UK have sought to reassure the public ahead of Euro 2016, which begins on Friday, even as concern rises following the recent arrest of a man attempting to stage an attack during the event.

Nonetheless, officials from all three countries acknowledged that an attack could still occur, even with extensive security in place.

Germany's Federal Criminal Police Office said there was "no concrete indication" of a threat, neither for Germany nor for France, but emphasized that the "danger of a terrorist act was real."

"The security authorities look carefully into all clues pointing to possible threats against the [Euro 2016]," said the office's spokesperson, Jens Beismann.

France, where the tournament will take place, has been especially sensitive to the danger, having been the target of a major terrorist attack in November of last year. The government has beefed up personnel across the country, where more than 90,000 police, soldiers and private security agents will be stationed to ensure the public's safety.

Regardless, President Francois Hollande said during a radio interview on Sunday that the threat would remain. "This threat will last for a long time, unfortunately, so we must do everything to ensure that the Euro 2016 is a success," he told France Inter radio.

Growing concerns over possible attack

Concerns over a possible incident grew after Ukraine's security agency said it had apprehended a Frenchman who had travelled to the country to acquire weapons for staging an attack during the tournament. A right-wing nationalist, the man reportedly intended to blow up a mosque, a synagogue and various bridges and other forms of highway infrastructure.

Britain's foreign office also warned on Tuesday that stadiums could be targeted, and advised fans attending the games to be vigilant at all times.

"During Euro 2016, stadiums, fan zones, venues broadcasting the tournament and transport hubs and links represent potential targets for terrorist attacks," a statement from the office read.

However, the government also emphasized that their advice was not in response to a specific threat.

blc/kms (AFP, SID, Reuters)