ISIS militants capture Tal Afar Monday June 16,2014

Another Iraqi town fell to ISIS militants this morning, solidifying their hold in the north of the country, as evidence of the jihadists' brutal reign intensified with shocking images of fighters massacring helpless prisoners.

Tal Afar, close to the Syrian border, was taken before dawn this morning, the town's mayor said. It is due west of Mosul, Iraq's second city, which fell to the jihadist fighters last week.

Mayor Abdulal Abdoul said that his town, 260 miles north-west of the capital Baghdad, was taken just before dawn. Residents in the town confirmed the occupation.

Tal Afar, which has a population of 200,000, contains a mixture of Shiite and Sunni Muslims. It is also just miles from an Iraqi airbase.