Discovered in northeastern Syria, the ruined city of Hamoukar appears to have been a large city by 4,500 B.C., said archaeologists Clemens Reichel and Salam al-Quntar, who co-directed Syrian-American excavations on the site.

Reichel, a research associate at the Oriental Institute of the University of Chicago, and al-Quntar, of the Syrian Department of Antiquities, jointly announced their discoveries on Thursday.

Photo of Clemens Reichel archaeologist

They said Hamoukar was a flourishing urban center at a time when cities were thought to be relegated hundreds of miles to the south.

The site is in the upper edges of the Tigris and Euphrates Valleys, near the Iraq border. Reichel said it may have been settled as long as 8,000 years ago.

Scholars had long believed that urbanized societies started and were isolated in Uruk, in southern Mesopotamia. But excavations that started in 1999 at Hamoukar and at other sites in central Syria led to new ideas about the how urban culture spread in the region. Ancient Mesopotamia was a region that includes Iraq and parts of Syria.

This year, the Syrian-American excavations discovered evidence of the battle that toppled and burned Hamoukar's walls and ended the city's independence. Researchers found that invaders likely hurled more than 1,200 sling-fired bullets at Hamoukar and more than 100 heavy, 4-inch clay balls.

"The whole area of our most recent excavation was a war zone," Reichel said.

The ruins have preserved not only local pottery and artifacts, but also vast amounts of Uruk pottery.

"The picture is compelling," Reichel said. "If the Uruk people weren't the ones firing the sling bullets, they certainly benefited from it. They took over this place right after its destruction."

Reichel said if Hamoukar's residents were taken by surprise it will give researchers plenty to study because their possessions likely were buried with them under the debris.