Kennington tube station in London has been closed to the public after a man allegedly stabbed another on the train, reported Mail Online.
The man was transported to a nearby hospital where he is said to be battling for his life.
Another stabbing allegedly took place this afternoon at Beckenham Junction.
The Kennington underground station was shut down due to a "customer incident," confirmed Transport for London (TfL).
A man on social media platform X said the train halted at Kennington before passengers were ordered to get off. The social media user said, "Our southbound Northern Line train stopped at Kennington and the driver asked us to get off the train (knowing someone was stabbing people)."
"Why not keep us on the train until the culprit had been detained?"
"I also was on the same train and overheard from medical staff storming in that two people were in real danger," another commented.
The connection between the Kennington and Beckenham incidents remains unconfirmed.
Authorities are actively looking for the assailant. They have issued a call for any witnesses to step forward with relevant information.
A harrowing video captures the attacker wielding a large blade, overpowering the victim on the moving train. A passenger can be heard yelling at the attacker to stop what he is doing.
"I'm on the train to Beckenham Junction and this man's stabbing someone on the train," a witness said.