ISTANBUL — Sixteen Turkish construction workers abducted four weeks ago by a Shiite militia in Iraq were released on Wednesday, Prime Minister Ahmet Davutoglu of Turkey said in a statement on Twitter.

The workers were among 18 employees of a Turkish construction company, Nurol Insaat, who were kidnapped in Baghdad on Sept. 2.

The group, which identified itself as the “Death Squads,” demanded that Turkey lift a siege on several Shiite towns and villages in Syria, claiming that they were under threat by Turkish-backed rebel groups.

“Our 16 workers have just been received by our Baghdad ambassador,” Mr. Davutoglu said on Twitter. “I talked to some of them on the phone.”