Greater Manchester Police (GMP) confirmed on Thursday evening that a man who drove a car into a crowd outside a busy synagogue earlier in the day, before stabbing two people to death and injuring four more, was a British citizen of Syrian origin.

Police said officers shot dead the suspected perpetrator outside the Heaton Park Hebrew Congregation Synagogue in the suburb of Crumpsall, north of Manchester city center, and declared a "terrorist incident."

They said the attacker wore a "vest which had the appearance of an explosive device" but which turned out not to be functional.

GMP added that three more people have been arrested in connection with the attack, describing them as "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."

Officers confirmed that the two dead victims were Jewish, killed on Yom Kippur, the holiest holiday in the Jewish calendar.

Earlier on Thursday, Assistant Commissioner Laurence Taylor, head of specialist operations for London's Metropolitan Police, said police forces across the United Kingdom would be "stepping up controls" at synagogues, other Jewish sites and more generally to provide "reassurance" to those communities affected.

"We will ensure every piece of intelligence and line of inquiry is investigated," he said.

What happened during the Manchester synagogue attack?

Police declared a major incident at 9:37 a.m. local time (0837 GMT/UTC) outside the Heaton Park Hebrew Congregation Synagogue in the north Manchester suburb of Crumpsall, and said that officers fired shots one minute later. 

GMP said paramedics were at the scene and that four members of the public had been injured, with both injuries caused "by the vehicle and stab wounds."

Police said they issued verbal warnings and fired warning shots, which the suspect did not heed, before shooting and disabling him.

Starmer 'appalled,' mayor urges people to avoid area

Prime Minister Keir Starmer, King Charles III and other political leaders all voiced outrage and sadness at the attack during the Jewish religious holiday Yom Kippur.

Manchester Mayor Andy Burnham told local BBC radio that it appeared to be a major event but also that "the immediate danger appears to be over."

Like the police, Burnham advised people to avoid the area as the emergency services respond.

Israeli Foreign Minister Gideon Saar said he was appalled by the attack.

"I am appalled by the murderous attack near the Heaton Park Synagogue in Manchester on the morning of the holiest day for the Jewish people: Yom Kippur," Gideon Saar said on X.

Saar went on to accuse British authorities of failing to curb what he described as rising antisemitism in Britain: "The truth must be told: blatant and rampant antisemitic and anti-Israeli incitement, as well as calls of support for terror, have recently become a widespread phenomenon in the streets of London, in cities across Britain, and on its campuses."

British Prime Minister Starmer also said the attack occurring on Yom Kippur made it particularly horrific.

"I'm appalled by the attack at a synagogue in Crumpsall," Starmer wrote online. "The fact that this has taken place on Yom Kippur, the holiest day in the Jewish calendar, makes it all the more horrific."

Starmer left a European summit in Denmark early to fly back to the UK to chair a so-called "COBRA" (Cabinet Office Briefing Rooms) meeting of committees coordinating the government response to national crises.

"I'm already able to say that additional police assets are being deployed to synagogues across the country and we will do everything to keep our Jewish community safe," Starmer said in Copenhagen before boarding his plane.

King Charles III said in a statement that he was "deeply shocked and saddened" by the attack, "especially on such a significant day for the Jewish community."

Manchester is home to roughly 30,000 Jewish people, making it the UK's second-largest Jewish community after London.

Edited by: Wesley Dockery