NEW YORK, October 4 (RIA Novosti) – Islamic State (IS) fighters in Iraq and Syria have switched tactics and started concealing their forces in response to a campaign of US-led airstrikes, Pentagon spokesman Rear Adm. John Kirby said Friday.

“Not surprisingly, they have gotten better at concealment. Before the airstrikes … they pretty much had free reign. They don’t have that free rein anymore, because they know we’re watching from the air,” Rear Adm. Kirby told reporters at the Pentagon.

“We expect that they will continue to change their tactics, based on the increasing pressure they’re going to get, not just from the air, but from the ground, with Iraqi security forces.”

In August, the United States started launching airstrikes against IS positions in Iraq. Earlier in September, US President Barack Obama unveiled a strategy to defeat the IS insurgency by creating an international anti-IS coalition and extending airstrikes to Syria. The US-led coalition is currently comprised of more than 60 countries, according to the State Department.

The IS, also known as the Islamic State of Iraq and Greater Syria (ISIS) or the Islamic State of Iraq and the Levant (ISIL), has been fighting against the Syrian government since 2012. In June 2014, the group extended its attacks to northern and western Iraq, declaring a caliphate on the territories under its control.