Updated

A U.N. humanitarian agency says some 66,000 people have been displaced in five months of fighting in Syria's crowded northern battlefield.

Turkish, Syrian government, Syrian opposition, and autonomous Kurdish-led forces have all been jostling for territory formerly held by the Islamic State group near the Turkish-Syrian frontier, as preparations are being made to attack the extremists' de facto capital, Raqqa.

The U.N.'s OCHA agency said Sunday that the Turkish and Syrian opposition campaign to capture al-Bab from IS militants displaced 40,000 residents. They captured the town on Feb. 23, after starting operations in November.

The office said another 26,000 residents have been displaced in fighting around Manbij, held by Kurdish-led forces, and al-Khafseh, held by IS militants. Al-Khafseh is home to the main water station for Aleppo, Syria's largest city.