A group of veterans on Wednesday came out in open support of Kulbhushan Jadhav, a former Indian Navy official arrested by Pakistan on charges of spying, and demanded "strong action" by the government in securing his immediate release and return home.

At a press conference, the military veterans even demanded reviewing of all treaties with Pakistan, including the water sharing agreement, to demonstrate such a strong approach.

The group, led by Aam Aadmi Party MLA Col (retd) Devendra Sehrawat, claimed that Jadhav was "abducted" from Iran by Pakistan's spy agency ISI and was taken to Pakistan.

The external affairs ministry had on Tuesday also alleged that he could have been "abducted" from Iran.

Sehrawat said veterans across the country will write to President Pranab Mukehrjee and Prime Minister Narendra Modi to take steps to secure his release.

Another veteran, Col (retd) Rajesh Bhardwaj claimed the ex-Navy officer was a batch mate of Union Minister Rajyavardhan Singh Rathore at the NationalDefenceAcademy academy, Pune. The veterans also said Rathore should also help in facilitating Jadhav's release.

Jadhav had been arrested recently in Pakistan, which described him as an officer of the Indian Navy, a claim debunked by the Indian government. India said he had no link with the government since his premature retirement from the Navy.

"We are all concerned about his arrest. We all feel that the ISI has conducted a full-scale operation under which he was abducted from Iran and then brought to Pakistan. We have cross-checked this with Iranian officers who had trained with us at the NDA," said Sehrawat.

Pakistan armed forces had on Tuesday released a video purportedly of Jadhav in which he admitted to having been involved in terror activities in Balochistan, a charge rubbished by India.

"Jadhav was made to give statements under duress," Sehrawat said.

Maj (Retd) T C Rao, another veteran and convenor of the Indian Martyr Foundation, demanded that the Indian government summon the Pakistan High Commissioner and raise the issue with him.

"The government needs to put pressure on the Pakistani government to ensure release of Jadhav. We demand that all treaties with Pakistan including the water sharing agreement and trade concessions be reviewed. It also needs to demonstrate a strong action in this case," Sehrawat said.

Bharadwaj said he had trained with Jadhav at the NDA.

"He was a brave officer of the Indian Navy. It's sad that the government is disowning him now. I have been trained with Jadhav. He was my senior at the NDA. In fact, he and Union Minister Rajyavardhan Rathore were batch mates at the NDA. He (Rathore) should help in ensuring his release," Bharadwaj added.