BAGHDAD — British archaeologists said Thursday they have unearthed a sprawling complex near the ancient city of Ur in southern Iraq, home of the biblical Abraham.

The structure, thought to be about 4,000 years old, probably served as an administrative center for Ur, around the time Abraham would have lived there before leaving for Canaan, according to the Bible.

The compound is near the site of the partially reconstructed Ziggurat, or Sumerian temple, said Stuart Campbell of Manchester University’s Archaeology Department, who led the dig.

“This is a breathtaking find,” Campbell said, because of its unusually large size – roughly the size of a soccer field. The archaeologist said complexes of this size and age were rare.

“It appears that it is some sort of public building. It might be an administrative building, it might have religious connections or controlling goods to the city of Ur,” he said.

The complex of rooms around a large courtyard was found 12 miles from Ur, the last capital of the Sumerian royal dynasties whose civilization flourished 5,000 years ago.

Campbell said one of the artifacts they unearthed was a 3.5-inch clay plaque showing a worshipper wearing a long, fringed robe, approaching a sacred site.

Beyond artifacts, the site could reveal the environmental and economic conditions of the region through analysis of plant and animal remains, the archaeological team said.

The dig began last month when the six-member British team worked with four Iraqi archaeologists to dig in the Tell Khaiber in the southern province of Thi Qar, some 200 miles south of Baghdad.

Decades of war and violence have kept international archaeologists away from Iraq, where significant archaeological sites as yet unexplored are located. Still, the dig showed that such collaborative missions could be possible in parts of Iraq that are relatively stable, like its Shiite-dominated south. The team was the first British-led archaeological dig in southern Iraq since the ’80s.