A fourth man has been arrested after a 16-year-old boy was murdered in Wolverhampton.
The teenager died after being found with stab wounds in Warnford Walk, Merry Hill, at around 4.30pm on Monday.
He was pronounced dead at the scene.
West Midlands Police said a 23-year-old man was arrested on suspicion of murder at around lunchtime on Tuesday.
It follows the arrests of two other men – both aged 22 – on suspicion of the same offence, and a 39-year-old man being arrested on suspicion of assisting an offender earlier on Tuesday.
All four remain in custody.
The force said: “The boy’s family are being supported by our officers and are being updated as this fast-moving investigation continues.
“We also understand how upsetting this incident is for people in the area and across our city as a whole.
“Local officers have stepped up patrols, so please do stop and talk to them if you need reassurance or want some advice.
“Teams across Wolverhampton Police are working every day to protect the public and young people from violence, in particular knife crime, with regular patrols crime hotspots.
“We have a number of dedicated teams who, along with our partners, are focused on keeping our youngsters safe
“The investigation into yesterday’s devastating incident continues and we’d ask anyone who does have information to get in contact.”
Anyone with information that could help the inquiry is urged to contact the force via 101, quoting incident 3421 of September 18.