Police arrested a 46-year-old man after he injured four pedestrians with a box cutter in three separate attacks over 1-1/2 hours. His rampage began in Kwun Tong about 8.30am and ended when he was arrested in Sau Mau Ping just after 10am, leaving three people with deep cuts to their thighs and one with minor injuries. Police said the man, who appeared to have mental problems, did not know the victims and had no obvious motive. The first attack was on a 44-year-old woman in Mut Wah Street, Kwun Tong. "As she was waiting to cross the road, the culprit suddenly squatted behind her, slashed her left leg and fled on foot," said Superintendent Remus Chong Siu-hing, assistant Sau Mau Ping district commander (crime). He said the victim escaped serious injury as she was wearing jeans. She went to United Christian Hospital for treatment and made a report to police. About an hour later, a 22-year-old man was attacked in Tsui Ping Road, about 800 metres from the first attack. Police said he suffered deep cuts to his thighs and was sent to hospital. The culprit fled before police arrived. At about 10am a man, 64, and his wife, 49, were attacked as they waited at a bus stop in Hong Ning Road, about 50 metres from Sau Mau Ping police station. "It happened all of a sudden. I couldn't see him as he attacked me from behind," the man said. Each of the two victims had to have about 20 stitches in their thighs. Within three minutes, officers from the Kowloon East emergency unit arrested the suspect outside Hong Ning Road Park, about 200 metres from the third crime scene. Officers found a box cutter in his trouser pocket. Police said there was no motive for the attacks and the suspect did not know the victims. "He was emotionally unstable and talked to himself after being arrested," Chong said. "It appears he has mental problems and a violent tendency." Last night, the man was sent to United Christian Hospital to check his mental condition. Police arrested him for wounding and no charge had been laid. The unemployed man, with no history of mental illness, lives with his wife in Hung Hom. Police said he had been arrested on Saturday after being accused of attacking his neighbour with a frying pan during a dispute. The latest crime figures show there were 333 reports of wounding in the first three months of this year, a 13 per cent drop from 384 a year ago.