Fans of a French soccer team stormed the pitch and launched flares at its own players after the club was relegated from the top division

• Saint-Etienne fans attacked their own players after being relegated from Ligue 1 on Sunday.
• Supporters stormed the pitch and threw flares and other projectiles at players.

Fans of French soccer team Saint-Etienne stormed the pitch and attacked their own players after the club was relegated from the country's top division on Sunday.

Saint-Etienne was beaten on penalties in a play-off by Auxerre, which will now replace Pascal Dupraz's side in Ligue 1 next season.

The defeat brings to an end 18 years in France's top flight for Saint-Etienne, which has won the French title 10 times.

Immediately after Remi Dugimont scored the winning penalty for Auxerre, hundreds of Saint-Etienne fans invaded the pitch at the Stade Geoffroy-Guichard, where some threw flares at the players.

Others were seen launching other projectiles including poles and chairs, while also setting fire to a number of seats in the stands.

Players and staff were forced to run down the tunnel to escape the trouble as police armed with shields and batons used tear gas to disperse the supporters.

According to Sky Sports News, two police officers and 17 fans were injured.

Watch the chaos unfold here:

In a statement, Saint-Etienne condemned the behavior of its supporters, accusing those responsible of violence towards "players, the security agents, the police, and the public."

The club said it "strongly condemns these acts, gives its full support to those affected and will initiate the necessary legal proceedings."

Saint-Etienne has already been sanctioned several times this season for the behavior of its supporters.

In November, the club was forced to play Clermont behind closed doors after protests from angry fans delayed a game against Angers.

It also had to play its final home game of the Ligue 1 season without fans, after supporters set off flares in the stands during a defeat to AS Monaco in April, which resulted the match being paused for 30 minutes.

As a result, one stand at the Stade Geoffroy-Guichard was closed for the match against Auxerre.