The Algerian security services on Friday seized a workshop for manufacturing firearms and ammunition in Biskra province, some 400 kms to the southeast of Algiers.Two workers, a man and his son, were arrested at the site, located at the basement of a house in the area.The police seized five guns, shooting rifles, 10 knives, five kilograms of gunpowder, 400 ready-to-use bullets and arms making equipment.The authorities are investigating whether the workshop has any links to terrorist groups.