Image source, Carl BessantImage caption, Pictures of a burning car outside the hospital have been widely shared on social media
Police cordons are in place in parts of Merseyside after a car exploded outside Liverpool Women's Hospital shortly before the national two minutes' silence for Remembrance Sunday was about to start.
Counter terror police are investigating, and arrests have been made.
Here's what we know so far:
Merseyside Police were called at 10:59 GMT to reports of a car explosion at Liverpool Women's Hospital.
A taxi carrying one passenger – a man – pulled up to the hospital and exploded shortly afterwards.
The passenger, who was declared dead at the scene, is yet to be formally identified.
The taxi driver is in hospital in a stable condition.
Police, firefighters and a bomb disposal unit attended the scene.
Phil Garrigan, chief fire officer of Merseyside Fire and Rescue Service, said the fire was "fully developed" when two appliances arrived shortly after 11am.
Image source, PA MediaImage caption, Specialist officers were seen on Rutland AvenueRaids
About two hours later, properties on Rutland Avenue near Sefton Park, and Boaler Street in Kensington were raided by armed officers.
Jim Clarke, BBC North West Tonight deputy editor, said the first raid happened at about 13:00 GMT on Rutland Avenue – roughly 0.75 miles from the hospital.
The second, on Boaler Street – about a mile from the hospital – took place an hour later, at about 14:00 GMT.
There was a heavy police presence, including police negotiators, outside the house on Rutland Avenue overnight.
Several residents were evacuated and a large cordon guarded by officers was put in place.
Who has been arrested?
Three men – aged 29, 26 and 21 – were arrested under the Terrorism Act after being detained in the Kensington area of the city.
Officers from Counter Terrorism North West are leading the investigation, supported by Merseyside Police and security service, MI5.
What are the police saying?
The Chief Constable of Merseyside Police, Serena Kennedy, offered her reassurance.
She said: "While I understand that today's incident may cause concern in our communities, it should be pointed out that events of this nature are very rare."
She added there would be an increased police presence on the streets of Merseyside and encouraged people to raise any concerns they may have with officers.
What has the hospital said?
Liverpool Women's Hospital says anyone with appointments at the hospital will notice an increased security and police presence on site. They asked anyone coming to the hospital to avoid bringing their vehicle for the time being.
The hospital is major obstetrics, gynaecology and neonatology research centre – the largest for its specialism in Europe. It featured on the popular Channel 4 programme One Born Every Minute.
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