A teenager was admitted to hospital after being stabbed on a double-decker bus in Kingstanding.
Police were called to the scene around 2.40pm on Thursday.
Agents were scrambled after age 16
The 16-year-old victim was on the number 5 bus that traveled through Kingstanding when he was stabbed, just before rush hour this afternoon.
Emergency services have rushed to the scene and a cordon remains in place along Kings Road.
This is what we know so far:
An adolescent stabbed in the chest aboard a double-decker bus is undergoing emergency treatment at an important trauma center.
The 16-year-old victim was on the No. 5 bus that traveled through Kingstanding when he was stabbed, just before rush hour this afternoon.
The emergency services have rushed to the scene and a cordon remains in place along Kings Road.
It is believed that the teenager traveled the double-decker bus to Sutton Coldfield when the attack occurred.
The air ambulance, a land ambulance and a paramedic officer were all called.
The victim received trauma care on the scene before being hastily from an earth ambulance on blue lights
A 17-year-old boy was arrested.
What did the police say?
A West Midlands police spokesman at BirminghamLive: "A 17-year-old boy was arrested after another teenager was stabbed on a King Road bus, Kingstanding, around 14.40 today (Thursday, November 8).
"A 16-year-old boy was taken to the hospital with a chest wound that is not believed to endanger his life at this stage.
"Surveys are at an early stage and anyone with information can contact us via Live Chat at west-midlands.police.uk between 8am and midnight, call 101 at any time or contact Crimestoppers anonymously on 0800 555 111.
"Register number of 1407 shares of 8/11/18."
What did the ambulance say?
A spokesman for the West Midlands Ambulance Service said: "I can confirm that we were summoned to Kingstanding shortly after 2:30 pm to the news of an assault.
" An ambulance, an officer paramedic and the Midlands Cosford air ambulances with a team of MERIT trauma on board witnessed the scene.
"When the ambulance staff arrived, they found a patient who suffered severe injuries.
" He received trauma treatment on stage before being taken from an earth-based ambulance on the blue lights at a major center traumatology for further emergency care. "
What do eyewitnesses say?
A 19 year old, who was on the scene before, said: "Everyone helped him and we all received towels, there was a lot of blood.
" He was stabbed his chest and the knife was missing his heart.
"He was sitting at the bus stop waiting for help."
A retiree, who lives near the scene of the attack, said the victim had "seen wrong"
A local mother, who preferred not being named, told BirminghamLive : "My daughter takes that bus every day to go to college. What's with these knives?
" It's not safe anywhere anymore. The poor boy and his family, I think they are also local. My daughter knows it. What they are going through now is unimaginable.
"Residents on the road took care of him, you gave Janet a cup of tea for you.The paramedics do an incredible job.They were stabbed in the chest, I really hope that everything is going well, this It should not happen, End of story. "
Janet Hart, 73, said," An 'ambulance has remained here for an hour', has looked bad.
" I hope I'm really praying for him.
"They took him to the ground ambulance to the Pimple, which was behind the police car. "
Another eyewitness said the victim was stabbed with what appeared to be a" snap knife ".
Video not available
Connor Moore, 21, said: "He was stabbed in the chest, blood was everywhere.
" We ran and received men and tissues to help him and help stop the bleeding.
"I had to walk though when I saw blood coming out of his chest."
What's going on now?
Police sealed the double-decker bus, believed to be a No. 5 service for Sutton Coldfield.
A stretch of Kings Road is also fenced off with motorists who are diverted from the scene.
Police were seen sweeping over a grazing area near the bus stop and doing door-to-door investigations.
It is thought that they are also exploring the area for possible CCTV.