LONDON – Police on Saturday were questioning six people arrested on suspicion of terror offenses after an attack on a synagogue in northwest England that left two men dead and Britain’s Jewish community shocked and grieving.

Jihad Al-Shamie, 35, was shot dead by police on Thursday outside the Heaton Park Congregation Synagogue in Manchester after he rammed a car into pedestrians, attacked them with a knife and tried to force his way into the building.

Congregation members Melvin Cravitz, 66, and Adrian Daulby, 53, died in the attack on Yom Kippur, the holiest day of the Jewish year. Police say Daulby was accidentally shot by an armed officer as he and other congregants barricaded the synagogue to block Al-Shamie from entering. Three other men are hospitalized with serious injuries.

Detectives say Al-Shamie, a British citizen of Syrian origin who lived in Manchester, may have been influenced by “extreme Islamist ideology.” He wore what appeared to be an explosives belt, which was found to be fake.

Police said Al-Shamie was on bail over an alleged rape at the time of the attack but had not been charged.

Three men and three women, aged between 18 and their 60s, were arrested in the greater Manchester area on suspicion of the “commission, preparation and instigation of acts of terrorism,” as police work to determine whether the attacker acted alone.

The attack has devastated Britain’s Jewish community and intensified debate about the line between criticism of Israel and antisemitism.

Recorded antisemitic incidents in the U.K. have risen sharply since Hamas’ Oct. 7, 2023, attack on Israel and Israel’s ensuing war against Hamas in Gaza, according to Community Security Trust, a charity that provides advice and protection for British Jews.

Some politicians and religious leaders claimed pro-Palestinian demonstrations, which have been held regularly since the war in Gaza began, had played a role in spreading hatred of Jews. The protests have been overwhelmingly peaceful but some say chants such as “From the river to the sea, Palestine will be free” incite anti-Jewish hatred.

Israeli Prime Minister Benjamin Netanyahu and his supporters have frequently accused critics of Israel or its conduct of the war of antisemitism. Critics see it as an attempt to stifle even legitimate criticism.

Chief Rabbi Ephraim Mirvis, the head of Orthodox Judaism in Britain, said the attack was the result of “an unrelenting wave of Jew hatred” on the streets and online.

Some also say the U.K.’s recognition of a Palestinian state last month has emboldened antisemitism — a claim the government rejects. Deputy Prime Minister David Lammy was interrupted by boos and shouts of “Shame on you” on Friday as he addressed a vigil for victims of the attack in Manchester.

Police in London urged organizers to call off a protest planned for Saturday to oppose the banning of the group Palestine Action, which has been labeled a terrorist organization by the government.

Prime Minister Keir Starmer said protest organizers should “recognize and respect the grief of British Jews this week” and postpone the demonstration.

The group Defend Our Juries said it would not cancel the protest, where hundreds of people are expected to risk arrest by holding signs supporting the banned group.

Member Jonathon Porritt said protesters would “demonstrate huge respect and real grief for those affected by the absolute atrocity at Heaton Park.

“But I don’t think that means that we should be asked to give up on our right to stand up for those who are being devastated by an ongoing, real-time genocide in Gaza,” he told the BBC.