There are 'strong indications' that a kidnapped Indian Catholic priest is still alive despite fears he had been crucified by his ISIS-linked captors on Good Friday, it has emerged.

Father Thomas Uzhunnalil was taken by Islamist gunmen who attacked an old people's home in Aden, southern Yemen, killing at least 15 people, on March 4.

The Archbishop of Vienna Christoph Schönborn had claimed that the 56-year-old had been murdered after reports emerged that the terrorists had threatened to crucify their hostage.

But he has since retracted his statement and there are now hopes that Father Thomas is still alive.

Indian Catholic priest Father Tom Uzhunnalil was kidnapped by ISIS gunmen in Yemen three weeks ago - but there are fresh hopes he is still alive

It was reported last week that several religious groups had received threats that Father Thomas would be crucified on Good Friday, but this was denied by his church in hometown of Bangalore.

However, Schönborn reportedly told a congregation gathered in St. Stephen's Cathedral in the Austrian capital that the priest had been crucified on Good Friday.

It is understood that he made the announcement on the basis of incorrect information from Archbishop Moras in Bangalore.

Bishop Paul Hinder of Southern Arabia, a region in Saudi Arabia, told the Catholic News Agency that he has 'strong indications that Fr. Tom is still alive in the hands of the kidnappers.'

'Cardinal Schönborn has already corrected his statement which he had made on the basis of the wrong statement of Archbishop Moras in Bangalore.'

A spokesperson for the cardinal yesterday admitted that while he did say that the priest had been crucified, he had no confirmation of Father Thomas' fate.

'The cardinal based his statements on news published on Arabic language web sites. The validity of this information has, however, not been confirmed,' said Arhdiocese Vienna's head of media relations, Michael Prüller.

Yemeni pro-government fighters gather outside an elderly care home in the southern city of Aden after it was attacked by ISIS-linked gunmen on March 4

'The cardinal doesn't himself have any sources that have confirmed the death of Father Tom.

'Thus, for the time being, there's still basis for hope that Father Tom is alive,' said Mr Prüller.

Yemeni authorities have blamed ISIS for the March 4 attack on the refuge for the elderly operated by Mother Teresa's Missionaries of Charity in main southern city Aden.

Four gunmen posing as relatives of one of the guests at the home burst inside, killing four Indian nuns, two Yemeni female staff members, eight elderly residents and a guard.

'According to our information, the extremists who attacked the elderly care home in Aden have kidnapped priest Tom Uzhunnalil, a 56-year-old Indian, who was taken to an unknown location,' a Yemeni security official said.

'We are aware that no group has yet claimed the criminal attack... but information points to the involvement of Daesh,' said the source, who asked to remain anonymous, using an Arabic acronym for IS.

However, members of Father Tom's order have denied that he is due to be crucified, saying they have no information on his health or whereabouts.

We have absolutely no information on Fr Tom,' Father Mathew Valarkot, spokesman for the Salesians' Bangalore province, told UCANews.

South African nuns called the Franciscan Sisters of Siessen were one of several groups who claimed they had been told Father Tom would be crucified on Good Friday

'But even today we do not know who has taken him and what their motives are because no one has claimed responsibility.'

The Vatican's Secretary of State Pietro Parolin said earlier this month that Pope Francis 'was shocked and profoundly saddened' to learn of 'this act of senseless and diabolical violence.'

Aden had been racked by lawlessness since Hadi supporters, backed by Gulf Arab military forces, drove fighters from Yemen's Iran-allied Houthi group from the city in July last year.

The Yemeni government has repeatedly vowed to restore security to the city but so far had had little success.

Al-Qaeda and IS have stepped up attacks in Aden, targeting mainly loyalists and members of a Saudi-led coalition battling Huthi rebels and their allies since March last year.

Al-Qaeda distanced itself from the mass shooting Friday, saying it was not responsible.