UEFA have fined Celtic 5,000 euros after their Green Brigade fans set off fireworks during a recent Champions League qualifying game. The 'improper conduct' sanction came after three flares were seen in Section 111 at Parkhead - which houses the supporters' group - during the game against Cliftonville on 23 July. This led to Celtic writing to season ticket holders in the area warning the section could be closed down if a repeat of the behaviour was noted.Celtic beat the Irish champions 5-0 on aggregate and wins over Elfsborg and Shakhter Karagandy saw them join Barcelona, AC Milan and Ajax in the group stages. The latest UEFA fine comes 20 months after Celtic were fined 25,000 euros over the conduct of their fans during a Europa League tie against Udinese in Italy. Following the 1-1 draw at the Stadio Friuli in December 2011, Celtic were charged with the 'displaying of a banner of an offensive nature and the setting off of fireworks by supporters'.