Referee Serdar Gozupiuk ordered both teams to return to the dressing rooms after fireworks were thrown on the pitch by home fans.
The referee had stopped the match for the first time before half-time for the same reason, and before that the match was briefly stopped after a trophy was thrown on the pitch.
Riots also broke out outside the stadium, forcing police to intervene, according to local press reports.
The main entrance gate of the Johan Cruyff Stadium was destroyed, according to photos posted on social media.
Feyenoord were 3-0 ahead of Ajax Amsterdam when the game stopped.
Ajax are currently going through a sporting crisis, and before the match against Feyenoord, the most decorated club in the Netherlands had just 5 points from 4 games and are in 13th place, while Feyenoord have 11 points from 5 games and are fourth in the table.
PSV Eindhoven lead the league with a full mark after 5 stages.