SINGAPORE - Paranoid that people were following him, a schizophrenic man stabbed three strangers with a pair of scissors in a span of three hours.

Ong Eng Huat, 44, attacked his victims from behind on the morning of April 12, after approaching them by the side of the road and at a void deck in Yishun and Ang Mo Kio. The attacks left the victims bleeding and in need of medical leave.

The jobless man also criminally intimidated four others in February and April, on one occasion holding the scissors to a cabby's neck and threatening to stab him if he would not drive.

On Thursday, Ong was sentenced to three years in jail, after pleading guilty to two of seven charges arising from his actions.

Ong's total jail time comes up to 10 years, after he received a further seven years plus six strokes of the cane for a drug related offence.

The court heard that he stabbed one of his victims around 7.30am on April 12, at a bus stop along Yishun Street 21. Ong hit him again despite his victim's attempts to walk away. When asked by the victim, 57-year-old Ong Kok Chhor, why he had been attacked, Ong said in Hokkien: "I had asked you to follow me. Why you did not follow me?"

District Judge Low Wee Ping said the Singapore Prison Service had assured him they could provide psychiatric treatment for Ong, who according to a report from the Institute of Mental Health suffers from Paranoid Schizophrenia. The report also said Ong's condition had caused him to commit the assaults.

Ong, who also has a history of drug offences, could have been jailed for up to seven years, fined, and caned for each of his hurt offences.