Two Athletic Bilbao security guards were stabbed by Marseille Ultras on Thursday, say reports in Spanish press.
Prior to the start of the Europa League clash on Thursday evening, a group of visiting fans launched fireworks in the direction of home supporters inside the San Mames and were quickly ejected.
Whilst outside the ground, it is reported that two security guards were stabbed with one receiving a wound to the neck.
Both were rushed to hospital, whilst police and security attempted to stop any further clashes.
Marseille, who won the tie 5-2 on aggregate, are now expecting to receive a fine for the fan outbursts by UEFA.
The incidents follow last month’s in Bilbao, which saw a police offer die after incidents involving Spartak Moscow Ultras.
Inocencio Alonso Garcia suffered a heart attack whilst on duty during the violent clashes, which saw more than 500 officers deployed for the Europa League second leg.
Five arrests were made as groups of Russian fans carrying weapons, clashed with home supporters, leading to Spanish Prime Minister Mariano Rajoy condemning the action.
Those clashes came on the same day a Russian man was arrested for attacking an England fan during Euro 2016, whilst travelling to the game in Bilbao.