The Dutch government is investigating if possible warning signs from Israel were missed in the events leading up to this week’s widespread attacks by local Arab and Muslim gangs on Maccabi Tel Aviv soccer fans in Amsterdam, Justice Minister David van Weel said in a letter to Parliament.

“An investigation is still being conducted on possible warning signs from Israel,” Van Weel said in his letter late on Friday evening.

“The Public Prosecution Service has stated that it aims to apply fast-track justice as much as possible,” van Weel said, adding that it is “the absolute priority” to identify every suspect.

Police on Saturday said four people remained in custody of the 63 people initially detained.

His letter came after he met with newly appointed Foreign Minister Gideon Sa’ar who traveled to Amsterdam after the attacks to oversee a rescue flight that brought the Israeli fans home.

“[I] emphasized that the Netherlands strongly condemns the violence and that there is no place for hatred and antisemitism,” van Weel said on social media platform X.

Sa’ar also met with met Geert Wilders, who heads the largest party in the Dutch government, and is known for his anti-Islam stance.

Wilders said he had assured Sa’ar of “our common interest to beat antisemitism and Jew hate and that radical Islamic values have no place in a free society.”

Van Weel’s letter came after Israeli officials said warnings had been sent to the Dutch.

A senior Israeli security official said Friday that Israeli security services had identified a “flare-up” on Dutch social media ahead of the game with calls by pro-Palestinian groups to hold a violent protest near the stadium.

“Due to this, the Mossad passed a warning to security services in the Netherlands with a request to immediately and significantly reinforce the security for Israelis in the area of the stadium and across the city, with an emphasis placed on hotels where the fans were known to be staying,” the official said.

However, he noted that Israel’s National Security Council had not been briefed on the threats and as such did not issue a warning to the public, including the some 3,000 fans who had traveled to see the match between Maccabi Tel Aviv and Ajax.

The official noted that the attacks, which he said “spread like wildfire” were apparently organized by Islamic elements in the Netherlands, and not by Iran, which has been accused of fomenting violent attacks on Israeli targets in other parts of Europe, particularly Sweden and Denmark.

Hebrew media also detailed that other Israeli ministries had also identified threats ahead of the game, with the Diaspora Affairs Ministry, which monitors antisemitism around the world, drawing up a warning document on Wednesday that highlighted the “very high risk” of such attacks, Channel 12 news reported Friday.

It said the warning was based on “indications” in social media monitored by the ministry, including overt online coordination of plans for violent demonstrations.

The ministry’s warning noted that protesters were being told not to carry Palestinian flags or other signs of Palestinian affiliation, and said the organizers were presenting the planned violent protests as constituting “a direct clash” with Israeli security forces and the Mossad.

Related: ‘They came in masses,’ ‘attacked us all’: Maccabi Tel Aviv fans describe Amsterdam horrors

The report said the ministry drew up its warning document in the light of what it saw as “the open encouragement of violence by the organizers of the demonstrations,” and the fact that there would be many children and identifiable Israelis in Amsterdam for the Maccabi Tel Aviv-Ajax soccer match.

The TV report said the Diaspora Affairs Ministry’s warning was shared with the Foreign Ministry and “a discussion was held.” But neither of the ministries, nor the National Security Council, issued warnings or guidelines to Maccabi or to the fans.

The report said the head of Shin Bet, Ronen Bar, is now in touch with his Dutch counterpart amid the ongoing investigation of suspected assailants who are in Dutch police custody, and what it classed as ongoing security issues.

It also said, without sourcing the claim, that there were “high alerts” at Israeli and Jewish facilities in Europe, and concerns about security at several forthcoming sporting events involving Israeli teams in the coming days.

While the outlet noted that Sports Minister Miki Zohar has recommended against Israeli fans traveling to matches in Europe, it stressed that the National Security Council, which issues such warnings, hasn’t done so and has no intention of changing the current travel guidance warnings.

Holland is on the NSC list of countries where a “Level 2” designation applies, indicating a “potential threat” and the need to take “precautionary measures.”

Israeli officials said 10 citizens were injured in the overnight violence. Hundreds more Israelis huddled in their hotels for hours, fearing they could be attacked.

Many said that Dutch security forces were nowhere to be found as the Israeli tourists were ambushed by gangs of masked assailants who shouted pro-Palestinian and anti-Israel slogans as they hunted, beat and harassed them.

Related: Israel decries ‘pogrom’ in Amsterdam as soccer fans come under attack by rioters

The mayor of the Dutch capital on Friday banned demonstrations for three days and gave police emergency stop-and-search power after the attacks which she called “antisemitic hit-and-run squads.”

Mayor Femke Halsema said Maccabi soccer fans had been “attacked, abused and pelted with fireworks” around the city, and that riot police intervened to protect them and escort them to hotels.

“Antisemitic hit-and-run squads” managed to evade a force of around 200 officers, she said.

Halsema said city police had been taken by surprise after security services failed to flag the match against Ajax Amsterdam as high risk.

Ajax is known as a soccer club with links to Amsterdam’s Jewish community because visiting fans had to pass the city’s Jewish quarter to get to the club’s former stadium. Ajax fans sometimes wave Star of David flags and chant the Dutch word for Jews.

On Friday, hundreds of people gathered for a pro-Israel solidarity rally in Amsterdam’s Dam Square.

Footage showed pro-Israel protesters singing Naomi Shemer’s “Jerusalem of Gold” with Dutch lyrics while flying Israeli flags in the main plaza.

Security has been tightened in the city, where a service was planned at a Jewish monument on Saturday.

The incidents in Amsterdam spurred fears of similar violence across Europe, however,  A basketball match in Italy involving Israeli team Maccabi Tel Aviv on Friday ended without incident after Israeli authorities called on fans to stay home.

“Calls continue on social media to harm Israelis and Jews, and there are concerns that the events of the last 24 hours may lead to a wave of copycat actions and further disturbances and attacks against Israelis abroad,” the Prime Minister’s Office says in a statement.

“In light of this, the National Security Council is advising Israelis to avoid attending Maccabi Tel Aviv’s game in Bologna and to avoid displaying visible Israeli or Jewish symbols as much as possible.”

In the end, there were no incidents at the EuroLeague match which Virtus Bologna won 84-77.

Ahead of the game, Bologna’s police chief further reinforced security, which was already high, and assigned a special escort to the Israeli team, Italian media reported.

“Growing antisemitism is unacceptable and horrible, and it is our duty to guarantee complete security to all our citizens of the Jewish religion,” Italian Prime Minister Giorgia Meloni said in a statement.

Agencies contributed to this report.