A 60-year-old man was stabbed at the ground floor of Block 43, Cambridge Road, yesterday afternoon.
The police said they were alerted to a case of voluntarily causing hurt using a dangerous weapon at 1.25pm.
The Singapore Civil Defence Force (SCDF) said it was alerted to the incident at 1.30pm and sent one ambulance to the scene.
The man, whose identity is unknown, was conscious when he was taken to Tan Tock Seng Hospital, said the SCDF.
It is understood that the victim - believed to be the owner of a second-hand goods store at the block - suffered injuries to his head and arm from a penknife and a screwdriver.
When The Sunday Times visited the scene at about 4pm, bloodstains could still be seen on the wall and floor outside the second-hand goods shop, where the attack is said to have occurred.
A woman who was taking care of the store - believed to be the victim's wife - declined to comment about the incident.
Residents in the area said they did not hear a commotion and were unaware that the incident had happened.
No information was available about the assailant.
Police investigations are ongoing.