Everton boss Ronald Koeman said he was "disappointed" by the unfortunate scenes in the stands during his side's 2-0 defeat of Hajduk Split in the first leg of their Europa League qualifying playoff at Goodison Park.
The match had to be halted for a few minutes in the first half when trouble flared in the away section that saw the hosts go in at the interval two goals up thanks to a Michael Keane header and an Idrissa Gueye strike.
It was shortly after Keane's 30th-minute goal that the crowd trouble broke out in the Hajduk section, with missiles being thrown, advertising boards being kicked over and some supporters almost getting on the pitch.