Archaeologists in Jordan are making the case that they've discovered a cave underneath one of the world's oldest churches, one that they contend may have been an even more ancient site of Christian worship.

But outside experts expressed caution about the claim.

Archaeologist Abdel-Qader al-Housan, head of the Rihab Center for Archaeological Studies, said this week that the cave was unearthed in the northern Jordanian city of Rihab after three months of excavation and shows evidence of early Christian rituals.

The cave is under St. George's Church, which some believe was built in the year 230, though the date is widely disputed.

That would make St. George's one of the oldest churches in the world, along with one unearthed in the Jordanian southern port of Aqaba in 1998 and another in Megiddo, Israel discovered in 2005.

The implication is that the cave underneath it is older still, possibly by centuries.

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Al-Housan said there was evidence that the underground cave was used as a church by 70 disciples of Jesus during the first century after Christ's death around A.D. 30, which would make it the oldest Christian site of worship in the world.

He described a circular worship area with stone seats separated from a living area that had a long tunnel leading to a source of water. He said the early Christians hid there from persecution.

A mosaic inscription on the floor of the later church of St. Georgeous above refers to "the 70 beloved by God and the divine" who founded the worship there.

Thomas Parker, a historian at the University of North Carolina-Raleigh, who led the team that discovered the church in Aqaba, said that while he hadn't seen the Rihab site, any such claim should be taken with a degree of caution.

"An extraordinary claim like this requires extraordinary evidence," he said. "We need to see the artifacts and dating evidence to suggest such an occupation in the 1st century A.D."

Parker asked how archaeologists could be certain whether the "cave was actually a center of Christian worship."

Parker also noted that mosaics are difficult to date unless there is a precise date in the text of the mosaic inscriptions themselves, and typical mosaic inscriptions with Christian themes are from the 5th to 6th century.

"It's quite possible that there was a cave with earlier occupation which was later converted to Christian use. But to make the jump that this was actually used by Christians fleeing Jerusalem in the 1st century A.D. seems like a stretch to me," Parker said.

Australian archaeologist Kate da Costa of the University of Sydney, who works in northern Jordan where the cave was found, also said the evidence needs to be confirmed by other archaeologists.

"And even if the cave can be proved to have been in use in the first (century) A.D., there needs to be additional evidence that it was used by Christians," she told the AP.

She also said that St. George's church is not universally accepted as the oldest church in the world.

Da Costa said a date of 230 for a constructed church "is over 200 years earlier than any other known church."

Archimandrite Nektarious, Bishop Deputy of the Greek Orthodox Archdiocese in Amman, nonetheless hailed the discovery, calling it an "important milestone for Christians all around the world and right here at home."

"It confirms that Christians in this region are not strangers," he said. "They are real citizens who have always had roots in this region from those days until the present."

The eastern shore of the Mediterranean was predominantly Christian from the time of the Roman imperial conversion in the early fourth century until Islamic invaders arrived in the mid-seventh century.

Conversion to Islam was mostly voluntary and sizeable Christian Arab minorities still exist in much of the Middle East.

Many Palestinians in the West Bank and Jordan are Greek Orthodox Christians, while Lebanon has a dozen officially recognized Christian sects.