Three people have been killed - and another three injured - in connected "horrific and tragic" attacks in Nottingham.
Police found two bodies in Ilkeston Road just after 04:00 BST, before being called to Milton Street where a van had attempted to run over three people.
A man was then found dead in Magdala Road.
Officers have arrested a man on suspicion of murder and locked down the city centre.
The 31-year-old is currently in custody.
Chief Constable Kate Meynell, from Nottinghamshire Police, said the force believed all three attacks were linked.
"This is an horrific and tragic incident which has claimed the lives of three people," she said.
"This investigation is at its early stages and a team of detectives is working to establish exactly what has happened.
"We ask the public to be patient while inquiries continue."
Prime Minister Rishi Sunak thanked the emergency services and said he was being updated on developments.
"My thoughts are with those injured, and the family and loved ones of those who have lost their lives," he said.
Labour leader Sir Keir Starmer also sent his "thoughts to all those affected and to the emergency services who are responding".
Alex Norris, Labour MP for Nottingham North, tweeted: "Awful news for our city to wake up to today.
"Our community's thoughts and prayers are with all those affected.
"Our gratitude is with our blue light responders for their work today also."
Witness Lynn Haggitt said she saw a van hitting two people in Nottingham."At half past five I saw a van pull up at the side of me," she said."It was white, all white. There was a police car behind it coming up slowly, no flashing lights."The man in the
driver's seat looked in his mirror and saw the police car behind him."She said the white van then drove up to "the corner of the street and went into two people"."The lady ended up on the curb, and then he backed up the white van and he went, speeded up Parliament Street with the police cars following him," she added.
A number of roads in the city have been closed while investigation work takes place. These are:
Ilkeston Road
Milton Street
Magdala Road
Maples Street
Woodborough Road (from junction of Magdala Road into the city)
Maid Marian Way at the junction of Parliament Street