Japan's Kishida vows to ensure safety during G7 summit

Speaking to reporters, Kishida said Japan must not allow acts of violence that attack the foundation of democracy.

Kishida's bomb scare was a sobering reminder of the assassination last July of former Prime Minister Shinzo Abe, who was shot with a homemade gun while campaigning for a parliamentary election.

Japanese politicians are campaigning for by-elections on April 23 for the lower house of parliament.

Chief Cabinet Secretary Hirokazu Matsuno says police have been instructed to boost security and the government would do what is necessary to ensure security when Japan hosts the May G7 summit in Hiroshima.

G7 foreign ministers gather on Sunday for a meeting in the resort city of Karuizawa, while the group's environment and energy ministers are meeting this weekend in Sapporo in northern Japan.