Story highlights The estimate represents a sharp increase over recent numbers provided by the US

This uptick in fighting in Mosul could be one reason for the new body count estimate

Washington (CNN) The US Special Operations head said Tuesday that the US and its allies had eliminated more than 60,000 ISIS fighters.

"We have killed over 60,000," Gen. Raymond "Tony" Thomas, commander of US Special Operations command, told a symposium Maryland.

Thomas oversees America's elite Special Operations troops, including Navy SEALs and Army Green Berets, which have played a large role in combating the terror organization, including raids against key leaders.

His estimate represents a sharp increase over recent numbers provided by the US and its allies.

A senior US military official told CNN in December that as many as 50,000 ISIS fighters had been killed, calling that figure a conservative estimate.

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