New Delhi, Sept. 12: Oman has found and secured the release of Father Tom Uzhunnalil, a Salesian priest from Kottayam in Kerala, 18 months after he was abducted by suspected Islamic State terrorists from Yemen, following weeks of quiet negotiations, Indian officials said.

The priest was flown to Muscat today, Oman's information ministry said in a statement, and will soon return to India.

"I am happy to inform that Father Tom Uzhunnalil has been rescued," Sushma said on Twitter, next to an image of the bearded priest, his hands crossed over his chest.

The priest was abducted in March 2016 by gun-totting men after they attacked a Missionaries of Charity home in Aden and killed 15 nuns and staff members, including four from India.

Yemen was - and is - in the middle of a brutal civil war, with the exiled government of Abdrabbuh Mansur Hadi, the Iran-backed Houthi rebels, the Islamic State and the Al-Qaeda in the Arabian Peninsula (AQAP) locked in a four-way tussle for territory.

Since April 2015, India has not had an embassy in Sana'a, closed following a massive evacuation form Yemen. The chaos in the country, and the absence of an embassy, hobbled Indian attempts at finding the priest.

But Sushma, who has gained significant public goodwill for her pressure on Indian missions overseas to assist nationals in need of help, repeatedly insisted that the government was doing all it could. Last year, a video surfaced online, suggesting that the abductors had crucified the priest. The video was found fake.

On two subsequent occasions, the abductors released videos where the priest was pleading, with the Indian government and with the Vatican, to facilitate his release.

In July, Sushma hosted the deputy Prime Minister of Yemen, who declared that "as per available information, Father Tom was alive and the Yemen Government has been making all efforts to secure his release," the Indian foreign ministry said then.

By then, Indian officials said today, Hadi's government - which controls Aden - had tracked down the abductors of the Indian priest, and had indicated to New Delhi that they were open to facilitating his release. However, they indicated, they would need formal mediation by another government with the militants.

India reached out to Oman, which borders Yemen, and which mediated the priest's release.

"In compliance with His Majesty Sultan Qaboos bin Said, Oman in coordination with the Yemeni parties have managed find a Vatican priest," the Oman information ministry said today, referring to the Sultan of Oman. "He has been transferred to Muscat from where he will return to his home in Kerala."

Officials refused to divulge whether the abductors made - and received - any ransom payment in exchange for the priest's release.