France’s famous Eiffel Tower, one of the world’s most visited attractions, was closed after a man carrying a rucksack was seen climbing the tower.

Anti-terrorist police supported by a helicopter could be seen at the iconic landmark following the alarm being raised at around 9am. But a search for the unidentified male failed to apprehend him and in the early afternoon, his whereabouts were still unknown.

The tower has since been blocked off by police and tourists have been asked to stay clear of the attraction for the day.

The tower finally re-opened at around 2pm, following a closure of more than five hours which is likely to have cost hundreds of thousands of pounds in lost revenue.

In what is being thought as an alternative explanation, police believe that the suspect might be an extreme parachutist hoping to jump off the building. “It’s happened in the past”, police said. In 2005, a Norwegian parachutist died while attempting to jump off the tower, according to Yahoo.

The French security agencies have reportedly pitched up their surveillance since the attack on Charlie Hebdo cartoonists in January this year.