New Zealand Prime Minister Jacinda Ardern on Thursday announced a ban of “military-style semi-automatic” weapons. The ban comes just six days after the mass shootings at two Islamic religious centers in the city of Christchurch. Fifty people died in the attacks. Ardern said New Zealanders could turn in their guns while officials develop a buyback program. The program could cost the government as much as $140 million. The ban includes all semi-automatic weapons and shotguns that can be used with removable magazines that hold more than five rounds of bullets. Ardern said the man charged in the mosque attacks used 30-round magazines that he bought “easily through a simple online purchase.” The prime minister added, “Every semi-automatic weapon used in the terrorist attack on Friday will be banned.” The ban does not include smaller guns or shotguns with non-removable magazines, which are commonly used among farmers and hunters in New Zealand.