Greater Manchester Police (GMP) said officers had been called to the incident at Heaton Park Hebrew Congregation Synagogue in Crumpsall, north Manchester, after a witness said they had seen a car driven at members of the public and that one man had been stabbed.
Armed officers responded and that a man, believed to be the offender, was shot, GMP said.
A Reuters photographer said there was a heavy police presence in the area. Ambulance crews were seen in protective body armour and helmets, and at least one person was seen being taken into an ambulance.
"Paramedics arrived at the scene ... and are tending to members of the public, currently four members of the public with injuries caused by both the vehicle and stab wounds," GMP said in a statement on X.
The North West Ambulance Service said it had dispatched resources to the area.
"We are currently assessing the situation and working with other members of the emergency services," the ambulance service said.
Andy Burnham, the mayor of Manchester, said it was a serious incident.
"I would say to people listening, firstly to avoid the area - it is a serious incident, but at the same time I can give some reassurance immediately to people that the immediate danger appears to be over, and Greater Manchester Police have dealt with it very quickly," he told BBC radio.
(Reporting by Catarina Demony and Phil Noble; Editing by Kate Holton and Michael Holden)
A police officer talks to a counter-protester holding an Israeli flag during a 'Stand Up to Racism' demonstration against the far-right, outside the Britannia Hotel in Canary Wharf, London, Britain, 31 August 2025. Protests by far-right groups outside hotels housing migrants have been increasing across the UK in recent weeks, with counter-protests also taking place. EPA/TOLGA AKMEN