NEW DELHI — An Indian Catholic priest returned to India on Thursday after being freed from 18 months of captivity by unknown kidnappers in Yemen.

Salesian Father Tom Uzhunnalil arrived in the Indian capital and met with Prime Minister Narendra Modi and other government officials.

The priest is from the Indian state of Kerala.

Speaking to reporters at the airport, Uzhunnalil thanked people who helped in his rescue.

“I am very happy, thank Almighty for making this day possible. I am grateful to all those people who have worked in their own way (to secure my release),” he said.

Uzhunnalil had been working as a chaplain at a retirement home for more than four years in the southern Yemeni city of Aden when he was kidnapped during an attack by unknown gunmen in March 2016. The attack left 16 dead, including four nuns belonging to the Missionaries of Charity, the order founded by Mother Teresa.

Uzhunnalil was released into the custody of the Sultanate of Oman on September 12, 2017.

Images show a bearded, gaunt Uzhunnalil descending from an airplane in Muscat, Oman. The priest said he had been transferred from Yemen by car to Oman, and then brought by air to the capital before continuing his journey to Rome.

The priest said he didn’t know his kidnappers’ identities or affiliations and believed their motive was ransom, although the head of Uzhunnalil’s Salesian order, Father A. F. Artime, said they had no knowledge of any ransom having been paid. The Indian government denied any ransom was paid.

Uzhunnalil stayed at the Salesian headquarters in Rome for two weeks to recover from his experience, and met Pope Francis the day after his release.

Crux staff contributed to this report.