The incidents, which occurred late on Saturday night, left one policeman and four civilians injured.

The prime suspect, identified to be a 30-year-old man, has been arrested, AFP reported.

The first incident of truck rampage was reported near the Commonwealth Stadium, where the driver of a white Chevrolet Malibu dashed into a police barricade. He got out of the car and stabbed the police officer using knife. The injuries, however, were not fatal.

An hour later, the driver of a U-Haul truck escaped the police checking underway in downtown. He subsequently went on a rampage attacking four civilians. The injured were rushed to hospital.

According to Rod Knecht, the attacks were carried out by a single person. To link the incident with terrorism, Knecht said the police had spotted a Daesh (ISIL or ISIS) flag at the front end of the Chevrolet Malibu, which struck a cop near the Commonwealth Stadium.

“Based on evidence at the scenes and the actions of the suspect, at 12:38 a.m. today it was determined that these incidents are being investigated as acts of terrorism,” Knecht said in the police briefing.