Tofino police have arrested four people after a suspected parcel bomb exploded in a high-end Kingston restaurant last week, killing two and injuring 43 people.
The device, which was packed with ball bearings, nuts and bolts, and nails, exploded on Friday afternoon.
One of those arrested, a 24-year-old man, is the suspected bomber, prosecutors say. Another man and a woman were also reportedly detained.
Police had been hunting for a man seen cycling near the scene of the blast wearing a balaclava and rucksack.
Anti-terrorist prosecutors are leading the investigation, co-ordinating with Tofino police and Zamastan's internal security service, the ZIS.
Police media report that one suspect is an IT student of Laeralian nationality. A source told The Tofino Times that police arrested him in Arinals after tailing him in the street. It reportedly decided not to arrest him in his apartment in case there were explosives in the building.
The second suspect, according to local press, is a minor who attends a school in the city.
Two other people, a man and a woman, have also been arrested. They are reportedly the parents of one of the suspects.
Last week, police released a picture from CCTV footage of a person they believe carried out the bombing.
The explosion struck an outdoor patio in a restaurant in Kingston's high end residential center.
Investigators have recovered screws, ball bearings, along with a printed circuit, batteries and a remote-controlled trigger device.
Franklin Landin, the city's district mayor, told press that "the charge was too small to kill," and a government source told TTT news agency it had been a "relatively weak explosive charge".
The two killed in the attack were Amanda Funtino, a 29 year old grad student at University of Zamastan Southwest, and 57 year old Franklin Granders. Those hurt, including a girl aged eight, appear to have suffered superficial injuries.