The French Open was momentarily brought to a halt on Wednesday after a deafening ‘sonic-boom’ left players visibly startled.
Before the cause of the loud bang was known, there was a brief moment of panic outside the grounds of Roland Garros in western Paris as police officers gave instructions to cordon off the area with the possibility of evacuating people.
Security officials sprinted down Boulevard d'Auteuil - a long road leading to one of the main entry gates - shouting into walkie-talkie radios.
But a few minutes later police revealed the cause of the noise - a fighter plane breaking the sound barrier.
“A very loud noise was heard in Paris and in the Paris region. There isn’t an explosion, it’s a fighter plane which has broken the sound barrier,” police wrote on Twitter.
“Don't clog up the help lines!”
French Open players visibly startled
One police officer on Boulevard d'Auteuil walked up to a security official guarding the gates and told them it was “false alert” before joining colleagues in his patrol car.
But with no forewarning, residents around Paris - along with fans and players inside Roland Garros - expressed their fears of an explosion on social networks.
About 45 minutes later, nearly 17,000 people had retweeted the reassuring news.
On Court Suzanne Lenglen, the second-biggest stadium at the French Open, German Dominik Koepfer was interrupted mid-serve by the bang’s loud clap.
His shoulders dropped and he pulled out of his serving action, then looked across the net at opponent Stan Wawrinka.
The Swiss veteran looked equally bemused as he stood perfectly still before play eventually continued.
Elina Svitolina was playing Renata Zarazua on Court Philippe Chatrier, the tournament's biggest stadium, when she heard the noise.
“I was a bit worried because I thought something bad happened. I looked at the chair umpire, he was little bit shocked as well,” Svitolina said after her match.
“You never know these days what can happen, what's going on. It was very strange, very loud, like something big dropped.”
Fans and members of the public flocked to social media bemused by the frightening noise.
Five years ago, as France were playing Germany in a soccer friendly at Stade de France, two explosions started a wave of deadly terror attacks in Paris.
The first explosion was largely unnoticed by the players on the field that day, but the second caused France defender Patrice Evra to stop playing with the ball at this feet as he looked up trying to comprehend what he was hearing.
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