Thousands of fans at a Strasbourg basketball stadium on lockdown during last night's shooting sang the French national anthem together in solidarity with the victims of the deadly attack.

Spectators at the game between SIG Strasbourg and Olimpija Ljubljana were told to remain inside the Rhenus Sport arena when the shooting broke out.

The nearby European parliament was also placed on lockdown.

Instead of panicking, fans joined together and calmly sang 'La Marseillaise' - the national anthem of France - in a tribute to those caught up in the violence in northeastern city.

Some 5,000 fans were told to remain inside the Rhenus Sport arena in Strasbourg while the Christmas market shooter was still active

In a video taken by SIG Strasbourg basketball club, the 5,034 fans can be heard singing the rousing closing refrain - 'Marchons, marchons! Qu'un sang impur Abreuve nos sillons!'

The lyrics are a battle cry, meaning 'Let's march, Let's march! May impure blood Water our fields!'

Composer Rouget de Lisle originally named the anthem 'Chant de guerre pour l'armée du Rhin' – or 'War song for the Rhine Army' – but it became known as 'La Marseillaise' after it was sung by revolutionaries from Marseilles as they descended on Paris in 1792.

Instead of panicking, the spectators joined in a rendition of the French national anthem 'La Marseillaise'

In a video shot by SIG Strasbourg basketball club, fans can be heard singing the closing words to the song's powerful refrain

The basketball fans were later evacuated safely, but the incident, in which a gunman opened fire at a Christmas market, claimed three lives. A further 14 were injured.

French authorities have launched an investigation and a manhunt for the suspect, 29-year-old Cherif Chekatt, who was known to the intelligence services as a potential security risk and would have been under partial surveillance.

On Tuesday, his home was searched by police, who reportedly discovered grenades and a rifle.