Dutch government and federation promise action after fan violence
The Dutch government also pledged a top-level investigation of the match.
The game on Wednesday was stopped for almost 30 minutes after Ajax midfielder Davy Klaassen was hit on the head by the lighter.
Kick-off had been delayed as fans set off fireworks. There were also anti-semitic chants.
Police said on Thursday they had arrested 22 people, including a 32-year-old man suspected of throwing the lighter.
The Dutch Football Federation (KNVB) announced later on Thursday measures to prevent such an "outrageous" incident from happening again.
"If a player or a referee is struck by an object from the crowd, the referee will immediately end the match," the KNVB said in a statement.
"We are fed up with this kind of behaviour."
The Dutch police union had earlier told tabloid newspaper Algemeen Dagblad the referee should have stopped the match altogether.
"Such bad behaviour should not be rewarded," the union said.
Games between the bitter Amsterdam and Rotterdam rivals are often flashpoints but there has been a rising incidence of football violence in the Netherlands.
Dutch Justice Minister Dilan Yesilgoz said the incident would be investigated "at the highest level."
She and Sports Minister Conny Helder will hold talks with the KNVB, clubs, municipalities and the police to find out what happened.
"If you continue like this, you will get a situation where even home supporters will be banned," Yesilgoz told the ANP news agency.
Dutch Prime Minister Mark Rutte said the violence was "intolerable".
"You don't touch players, coaches and referees. What happened here is totally scandalous," Rutte told a weekly news conference.
Feyenoord said they were closing a 2,000 seat section of the stand from which the projectile was thrown when they face Roma on April 13, in the quarter-finals of the Europa League.
"Feyenoord feel obliged to take this decision following the events," the club said in a statement, adding the individuals arrested faced a long-term stadium ban.
Referee Allard Lindhout stopped the game in the 63rd minute for almost half an hour after a lighter thrown from the stands hit Klaassen, who was left with a bleeding head wound.
Ajax eventually won 2-1 to qualify for the final, also set to be held at Rotterdam's De Kuip, where they will play PSV Eindhoven.
Klaassen, who scored his team's second goal in the 51st minute and tried to continue after the restart but left the pitch a few minutes afterwards, holding his head.
FIFA President Gianni Infantino urged Dutch authorities to take action.
"There is absolutely no place for violence in football, on or off the field," Infantino said on his Instagram account.
"Such events... have no place in our sport or in society all players have to be safe and secure to play the game, and I call on the relevant authorities to ensure that this is respected at all levels."
Dutch newspapers called for action.
"How long will this still go on?" asked the daily tabloid De Telegraaf in a headline.
"Yet again something went wrong in this classic match, where away supporters are in any case not allowed," the paper said.
