Aston Villa’s Europa League match against Young Boys on Thursday was temporarily halted because of violence in the away end at Villa Park.
Villa forward Donyell Malen was struck on the head by a plastic cup thrown from the away end while he was celebrating his 27th-minute opener.
The Dutchman’s head was cut but he did not receive medical treatment.
The match was then paused for five and a half minutes when objects were again thrown at Malen after he scored his second goal in the 42nd minute, with Young Boys captain Loris Benito running over to speak with the away fans.
Several seats in the away end were ripped out and thrown in the direction of the pitch.
BBC Radio 5 Live’s Tom Gayle, reporting from Villa Park, said: “Each Aston Villa goal has seen a hail of objects being thrown from the away section on to the pitch.
“This led to clashes with the police and stewards, with two people dressed head to toe in black being dragged away in handcuffs by officers.”
What will punishment be?
Uefa’s control, ethics and disciplinary body takes decisions about fan behaviour on a case-by-case basis.
Fines are the most common punishment for offences such as the throwing of objects, but for the more serious incidents a club’s supporters can be banned from attending away fixtures.
There are some similarities to the events in the 2023 Conference League final, when West Ham supporters threw cups onto the pitch and Fiorentina captain Cristiano Biraghi was left with a bloodied head.
Uefa fined the Hammers 50,000 euros (£43,000) and fans were banned from their next two European away games, although the second game was suspended for two years.
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