Japanese former Prime Minister Shinzo Abe has died, public broadcaster NHK said on Friday.

Mr. Abe, 67, had been delivering a stump speech near a train station in the western city of Nara when he was shot by an assailant.

Mr. Abe was airlifted to a hospital, where he was not breathing and his heart had stopped, officials said.

He was shot at about 11.30 am local time in western Nara, chief Cabinet secretary Hirokazu Matsuno said on Friday.

“Former prime minister Abe's condition is not currently known and we are checking the situation,” Mr. Matsuno told reporters at an emergency news briefing at the prime minister's office.

Mr. Kishida called the attack “dastardly and barbaric”.

Authorities have arrested a man who appeared to have shot Mr. Abe, 67, in the back. Police later raided the suspect's home.

Public broadcaster NHK aired footage that showed Mr. Abe holding his chest on the ground, his shirt smeared with blood, as several security guards ran towards him.

The fire department said he showed no vital signs upon being admitted to the hospital, NHK said on Twitter.

The man who was arrested appeared to be in his 40s and faces charges of attempted murder. His gun was confiscated by authorities, NHK reported, citing police officials.

NHK said two consecutive gunshots were heard during Mr. Abe's campaign speech before Sunday’s vote to elect politicians to the country's upper house of parliament.

Kyodo News said the former prime minister was not conscious and appeared to be in cardiac arrest when he was taken to hospital.

'Outstanding leader'

The US ambassador to Japan, Rahm Emanuel, said he was “shocked” by the shooting.

“We are all saddened and shocked by the shooting of former prime minister Abe Shinzo,” he said.

“Abe-san has been an outstanding leader of Japan and unwavering ally of the United States. The US government and American people are praying for the well-being of Abe-san, his family, and the people of Japan.”

Indian Prime Minister Narendra Modi said he was “deeply distressed” by the shooting, describing Mr. Abe as a “dear friend”.

“Deeply distressed by the attack on my dear friend Abe,” Mr. Modi wrote on Twitter. “Our thoughts and prayers are with him, his family, and the people of Japan.”

US Secretary Of State Anthony Blinken expressed his concern for Mr. Abe before a meeting with the Indonesian Foreign Minister.

“I do have to say before we meet, how deeply saddened and deeply concerned we are by the news coming from Japan about the attempt on the life of prime minister Abe,” he said.

“We don't know his condition. We do know he has been shot, and our thoughts and prayers are with him and his family, with the people of Japan. This is a very, very sad moment and we are waiting [for] news from Japan.”

A White House representative said: “We are shocked and saddened to hear about the violent attack against former Japanese prime minister Shinzo Abe. We are closely monitoring the reports and keeping our thoughts with his family and the people of Japan.”

British Prime Minister Boris Johnson said he was utterly appalled and saddened to hear about the "despicable attack".

"My thoughts are with his family and loved ones," he wrote on Twitter.

Mr. Abe served two terms to become the country's longest-serving prime minister before stepping down in 2020 due to ill health.

He has remained a dominant presence over the ruling Liberal Democratic party, controlling one of its major factions.

Prime Minister Fumio Kishida suspended his election campaign after Mr. Abe's shooting and was returning to Tokyo, according to reports.