French football authorities will demand answers from Lens after home fans invaded the pitch and confronted rival supporters at half-time in their Ligue 1 derby against Lille. 

Lens general manager Arnaud Pouille is certain the Ligue de Football Professionnel (LFP) will begin disciplinary proceedings against his club, following the ugly scenes at their Stade Bollaert-Delelis home. 

Lille may also be summoned as league chiefs unpick the unsavoury scenes that saw fans from each club contribute to a volatile atmosphere. 

Tension spilled over at the interval as scores of Lens supporters raced across the pitch towards those who had travelled to support Lille. 

Pouille said the north-east derby trouble was bad news for the clubs because it would be "the image of the region that is affected". 

"I have a clear idea of what happened," he said, according to L'Equipe. "But I don't want to influence anyone by speaking out. It is not under our authority. 

"There were a few actions that ignited the powder and a reaction that is damaging. But in these cases, speaking out is complicated because whatever you say, you make it feel like you want to influence. 

"We condemn any act of violence. There are proceedings that are ongoing. At the level of the LFP, at the level of justice, there will be complaints filed by the club, and by the opposing club also from what I understood." 

Lille announced on Twitter at half-time that the game was under threat, stating: "Following a pitch invasion from the home end of the stadium, an emergency meeting is taking place to decide whether the match will be continued or abandoned." 

Pouille said he had spoken to Lille president Olivier Letang at half-time, as the trouble occurred. 

The recent abandonment of the match between Nice and Marseille due to supporter violence was followed by Nice receiving a two-point penalty, one of which was suspended. 

According to Pouille, the trouble at Saturday's match could not be compared to the mayhem in that fixture. 

"It is not at all the same circumstances," Pouille said. "No players in the [Lens-Lille] game were affected, the main events took place at half-time. 

"Yes, there will certainly be a summons from the disciplinary committee, we will discuss with them at that time." 

Lens went on to win 1-0 against last season's champions, who have made a rocky start to their title defence. 

Lille head coach Jocelyn Gourvennec said he had been unaware of the precise circumstances behind the trouble. The game was held up, with 40 minutes between the end of the first half and the beginning of the second. 

"Half-time incidents? We had already returned to the locker room. I don't really know what happened," Gourvennec said. "We were informed by the delegates and Mr Millot [referee Benoit Millot] who spoke to the coaches and captains. 

"It was just a bit long, it lengthened the half-time, we had to do a warm-up again, it was not ideal. I do not know more. I hope there were no injuries."