Tokyo - The mayor of the Japanese city of Nagasaki died early on Wednesday after being shot as he campaigned for re-election, police said, in a crime allegedly linked to an underworld gang.
Iccho Ito, 61, succumbed to wounds sustained late Tuesday when he was shot as he got out of a van at his election office facing Nagasaki's central train station, a police spokesperson in the southern city said.
Ito underwent emergency surgery late on Tuesday, but the hospital said a bullet had reached his heart and he did not regain consciousness after the operation. The police spokesperson said he had died of massive blood loss.
Gun violence is rare in Japan, which strictly controls arms possession.
But police said the suspect, identified as 59-year-old Tetsuya Shiroo, was affiliated with Japan's largest organised crime syndicate, the Yamaguchi-gumi.
Senior Nagasaki police official Kazuki Unebayashi said the assailant, who was taken into custody immediately after the incident, "fired several bullets at the back of the victim with an intent to kill him".
Public broadcaster NHK, quoting unnamed sources, said Shiroo had grievances with the city after his vehicle was damaged due to poor maintenance on a road several years ago.
"I hope that authorities will investigate the case thoroughly and get to the truth," Prime Minister Shinzo Abe said.
Ito was an outspoken pacifist who was born one month after the best-known event in Nagasaki's history - the world's second and last atomic bombing on August 9, 1945 that killed more than 70 000 people.
A political independent, he had been campaigning for another term in office ahead of elections scheduled for Sunday.
"At around 7.50 pm, I heard two gunshots, like bang, bang," the owner of a restaurant near the scene told NHK.
"At first I didn't think it was gunfire," he said. "But when I looked outside, a man was already apprehended."
Nagasaki has seen attacks on politicians before. In January 1990, a right-wing extremist shot and wounded then mayor Hitoshi Motoshima for saying he believed the late emperor Hirohito bore responsibility for World War II.
Japan's last political assassination was in October 2002, when a rightist stabbed to death Koki Ishii, an opposition lawmaker campaigning to expose corruption, outside his Tokyo home with a 30-centimetre (12-inch) blade.
The Japanese "yakuza" are active in underworld crime, and have interests in show business and other lucrative industries.
A report earlier this year by the National Police Agency said the Yamaguchi-gumi, headquartered in the western city of Kobe, had about 40 000 members and accounted for some 50 percent of Japan's underworld.
The Yamaguchi-gumi has reportedly been trying to branch out from its home ground, particularly in Tokyo, leading to a turf(territory) war earlier this year that resulted in rare shootings in the capital.
Last year, in his annual address marking the atomic bombing, Ito lashed out at the United States, North Korea, India and Pakistan for their nuclear arsenals, asking, "What is the human race doing?"
One witness to the shooting said he called emergency rescue teams as soon as he heard the gunfire.
"I just got off a bus and was walking through the bus terminal. I heard one bang. I only recall one. I thought a tyre(tire) might have burst," the unidentified witness told NHK.
"A person had fallen over and a lady was in a panic. Then it dawned on me that it was a gunshot," he said.
He said he saw five people tackle down the suspect. "He didn't appear to have resisted," he said.