New Delhi,  Former Congress President Rahul Gandhi on Friday expressed shock over the attack on former Japanese Prime Minister Shinzo Abe.

"Shocked to hear the news of the attack on former PM of Japan, Shinzo Abe, who has been instrumental in deepening Indo-Japanese ties. Prayers for his recovery. My thoughts are with his family," he tweeted.

Shinzo Abe, who was Japan's longest-serving Prime Minister, collapsed after he was shot at while addressing a crowd in Nara prefecture on Friday, state media said in a report, adding that the police have arrested a suspect.

According to state broadcaster NHK, the incident took place at around 11. 30 a.m. (local time) near the Yamatosaidaiji Station in Nara city while the 67-year-old former leader was making a speech for a Liberal Democratic Party candidate's election campaign.

The local fire department says that Abe is in cardiopulmonary arrest and is scheduled to be transferred by medevac to Nara Medical University Hospital in Kashihara City in the prefecture.

According to the BBC, the term cardiopulmonary arrest is often used before a death is officially confirmed in Japan.

The NHK report further said that a gunshot was heard on site and Abe was seen bleeding.

Meanwhile, the police have said that Abe appeared to have been shot from behind with a shotgun, the state broadcaster reported.