"The drivers of bulldozers came across four human remains near Chamchamal, 100 kilometers (60 miles)) south of the Kurdish city of Suleimaniyah, and we decided to halt all further work," said Lieutenant Colonel Mahdi Mohammed Ali, the local police chief.

"We are keeping an eye on the site while waiting for the arrival of specialized teams from the human rights department" of the Patriotic Union of Kurdistan, the party administering Suleimaniyah province.

"The area was used by members of Saddam Hussein's security services to screen those entering and leaving Kurdistan after 1991," he said, referring to the time after which the north became increasingly outside the countrol of the central government.

"We think that Saddam's people, who manned the post until the fall of the regime, were responsible for many kidnappings and executions," he said.

Numerous mass graves of Kurds in the north and Shiites in the south have been discovered since the fall of Saddam's regime in 2003.