The five suspects were arrested from the north central region of Horowpothana on the day when eight Tamil National Alliance members voted against the Emergency declared in the country.
The dogs will be trained in in the Explosive Ordnance Disposal Squadron of the Sri Lanka Engineers within a few weeks before they are tasked with specific roles.
Inspector General of Police Pujith Jayasundara resigned over failures that led to the deadly Easter bomb attacks.
The area near the Savoy Cinema at Wellawatta, South Colombo was cleared and the controlled explosion was carried out by the bomb disposal squad to check the motorcycle which had no owner.
The police have arrested over 10 people from the Muslim minority concentrated areas of Aluthgama and Beruwela in south of Colombo.
The arrested suspects include the driver of a van allegedly used by the suicide bombers and the owner of a house where some of them lived.