Police detectives have launched investigations into two serious incidents of robbery and attempted robbery in Hamilton on Thursday in which a 70-year-old man was sent to hospital and a taxi driver was roughed up.

The senior citizen was walking at the junction of Curving Avenue and King street at 1.30 p.m. when three black men ? believed to be between 18 and 20 and wearing white t-shirts and khaki pants ? jumped him.

The trio took away seven rings, two gold chains and a cellular phone from the victim, who suffered bruising to his leg, arms and chest.

At 3.28 p.m., three men were involved in an altercation with a man and his wife at the junction of Queen and Church Streets. Police report that one of the three young men reached into a stationary car and slapped a passenger on his chin and left shoulder.

When the driver got out and confronted the trio, he was punched, as well. His wife and the passenger of the car were also roughed up.

A knife was brandished by the trio ? described as being between 18 and 20 ? before they fled the scene in a taxi.

Once at their destination of Curving Avenue, one of the trio grabbed onto the cabbie?s gold chains but was stopped. The driver instructed them to get out. His injuries were superficial.

The suspects in the Queen Street incident are described as a light brown-skinned male, about five feet, nine inches, of average build ? around 160 pounds, narrow, slim features, light mustache, close haircut.

The man was sporting a big gold coloured chain around his neck, dressed in a white sleeveless vest and jeans.

Suspect two is dark brown-skinned, five feet, four inches in height, thin build and wearing a blue short sleeve t-shirt. The third man is also dark brown-skinned, five feet tall.

Police are appealing to members of the public who have witnessed these incidents or may have information pertaining to them to contact their respective Police Station, Police Headquarters at 295-0011 or the confidential Crimestoppers Hotline at 1 (800) 623-8477.