Iraqi Counter-Terrorism Service forces "continue to conduct ground clearance operations to destroy any remaining [ISIS fighters] on the island", officials said.
While ISIS was routed from the last of the territory it held in Iraq in late 2017 and ousted from its last bastion in Syria early this year, the group has continued to carry out targeted killings and arson of crops in both countries.
Tuesday's strikes were meant to disrupt the hardline Islamist group's ability to hide in the thick vegetation on the island, the coalition statement said.
A tweet from OIR Spokesman Col. Myles B. Caggins, which aired the video, said: "Here's what it looks like when @USAFCENT F15 and F35 jets drop 36,000kg of bombs on a Daesh [ISIS] infested island".
Following the early morning strikes, ground clearance operations conducted by the Iraqi special forces were underway on the island, the USA -led coalition said in a statement in the afternoon.
Two F-35s - the most advanced fighters in the USA military's inventory - were used to conduct an "airstrike using a Joint Direct Attack Munition to strike an entrenched tunnel network and a weapons cache" belonging to the Islamic State deep in the Hamrin Mountains in the northeast part of the country, officials said of the April mission.
But since their defeat, ISIS cells have sprung up in the region and carried out deadly bombings.
Special Operations Joint Task Force and Operation Inherent Resolve commander Maj Gen Eric T. Hill said: "We're denying Daesh the ability to hide on Qanus Island". IS controlled large swathes of Syria and Iraq where they declared a caliphate in 2014.
He added: "We know they are hiding in ungoverned spaces and Daesh is still trying to regenerate".
He declared that the coalition will "stay here and support the ISF [Iraqi Security Forces] until no longer needed".
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The ISF, supported by the coalition, are attacking Daesh networks and degrading their capabilities.
"We do see some unraveling of their communications".
They reported they removed 4,000 pounds of explosives from the battlefield within the two months. By comparison, in 2017, aircraft dropped 5,075 in the month of August, more than 20 times last month's total and the highest number of munitions recorded in a single month's time, the data shows.