Brentford say they are working with the police following a “dangerous” incident in which a rugby ball was kicked from a height towards the pitch during their Premier League game with Liverpool.

A video on social media shows a man standing on a rooftop near the Gtech Community Stadium, kicking a rugby ball towards the pitch while others laugh and cheer.

Another clip from inside the ground shows the rugby ball being taken away from the pitch by a member of staff as play continued.

In a statement, Brentford, who were beaten 2-1 on Saturday, said “such behaviour is dangerous and potentially very harmful”.

“The matter has been referred to the police and the club is supporting the relevant authorities in their investigation to help identify those responsible and take appropriate action, which may result in criminal prosecution,” the statement added.

“The matchday safety of fans, staff, players and officials is of utmost importance, and the club will support all efforts to ensure action is taken.”

Brentford, who had Yehor Yarmolyuk and Vitaly Janelt both sent off in the second half, are sixth in the league table after the defeat.