The Manchester synagogue terrorist called 999 and pledged allegiance to Islamic State after he launched the attack.
Counter Terrorism Policing North West has confirmed that knifeman Jihad al-Shamie, 35, called police in the initial stages of the attack last Thursday.
Melvin Cravitz, 66, and Adrian Daulby, 53, were both killed and several others were injured during the attack, which took place on Yom Kippur, the holiest day in the Jewish calendar.
A spokesperson for Counter Terrorism Policing North West said: “We can confirm that, in the initial stages of the attack outside the Heaton Park Hebrew Congregation Synagogue, a call was made by the attacker to police claiming to pledge allegiance to the so-called Islamic State.
“We are continuing to investigate the full circumstances and motivation behind what happened. The investigation is continuing at pace.”
Reports in The Sun say he told 999 operators: “I have killed two Jews in the name of the Islamic State.”
Shamie, who was on bail for an alleged rape offence, was shot dead by police minutes after he launched the attack, which was declared a terror attack by authorities.
Police are still working to establish the full details of the motivations of the 35-year-old attacker, who was a British national of Syrian heritage and was granted citizenship in 2006 as a minor.
Investigators do not believe he had ever been referred to Prevent, Britain’s counterterrorism programme, but did have a criminal history and police say he may have been influenced by an extreme Islamist mindset.
In a statement, his family condemned the attack, describing it as a “heinous act”.
It later emerged that two victims of the attack were shot by armed police as they sheltered inside the barricaded door of the synagogue.
Adrian Daulby, 53, died after he sustained a bullet wound, while another person was injured by a stray bullet.
Sir Stephen Watson, chief constable of Greater Manchester Police, said the victims’ bullet wounds “may sadly have been sustained as a tragic and unforeseen consequence of the urgently required action taken by my officers to bring this vicious attack to an end”.
The Independent Office for Police Conduct (IOPC), the police watchdog, has launched an investigation into the fatal shooting by armed officers.
The police chief said he welcomed that the police watchdog had found that “no misconduct is apparent” in the force’s response to the Manchester synagogue attack.
It comes after the Independent Office for Police Conduct (IOPC) said the three armed officers who fired their weapons while responding to the attack outside Heaton Park Synagogue in Crumpsall are being treated as “witnesses to the investigation”.
Four people arrested on suspicion of preparing terrorist acts remain in custody after police were granted a further five days to question them on Saturday.
There are two men, aged 30 and 32, and a woman, 61, all arrested in Prestwich, and a 46-year-old woman arrested in Farnworth.
An 18-year-old woman and a 43-year-old man who were arrested in Farnworth, were released with no further action on Saturday.
Police said they have further releases planned for today, but have not concluded the investigation.