MANCHESTER, United Kingdom (AFP) — An attacker ploughed a car into a crowd outside a packed synagogue in Britain on Thursday, a Jewish holiday, before going on a stabbing spree, killing two people and leaving three wounded, police said.

Police said they shot dead the suspect, later identifying him as a UK citizen of Syrian origin, and arrested three other people within hours of the attack in the city of Manchester, which took place as Jewish communities around the world marked Yom Kippur, the holiest holiday in the Jewish calendar.

The two dead victims were Jewish men, police in the northwest English city confirmed, as counter-terror police declared it a “terrorist incident.” Three other people were in hospital with serious injuries, police said, after saying four had been wounded.

The three people arrested were “two men in their 30s and a woman in her 60s,” who were in custody “on suspicion of commission, preparation and instigation of acts of terrorism,” said Greater Manchester Police.

The attacker wore a “vest which had the appearance of an explosive device,” but police revealed Thursday evening it was not functional.

As night fell on Thursday, Orthodox Jewish worshippers emerged from packed synagogues in Manchester after a day of prayers and fasting to learn about the attack, having switched off phones and computers for the day.

Aryeh Ehrentreu, 56, who spent the day praying in a synagogue minutes away, said he had heard the ambulances arriving.